how to choose window tiling manager?

I personally use and recommend Sway.
If you are the kind of person who cares about the culture around the software that you use, avoid hyprland. It's creator is antilgbt and their discord server is pretty toxic. I also happen to think their documentation sucks.
- You can join the discord and check it for yourself. Been on it since December 2023 but never once saw one toxic comment. Also don't know since when but the discord has no off topic conversation. The discord screenshots in drews blog were 2-3 years ago.
  Hyprland already has explicit sync enabled unlike sway. Sway is good too but at that pount I'd just be using i3 which is more stable.

My recommendation is to just try bunch of them and see which one fits your needs or you like using the most.
Try both manual tiling and auto tiling for both X11 and Wayland, one will eventually stick.
I started with AwesomeWM, then tried bunch of other ones , and to my surprise, I found myself using DWM (flexipatch) the most. I'm planning to transition to Hyprland soon.
Just use what you like and don't pay much attention about the reviews.

I think the best is you read and inform about each of them and then choose. I'm not sure what answer you expect here. Do you know Python? Well then maybe Qtile is for you. Do you want switch to Wayland? Some window manager are Xorg/X11 only. Some are configured in a simple configuration file and some are configured by programming in a programming language.
Do you want an auto tiler or manual tiling? i3 is an example of manual tiling, which I did not like to do. Auto tiling means you don't choose what position, it will always determine it automatically based on the rules the layout has. Some tiler have multiple layouts and rules you can switch between.
How to choose a window tiling manager? By reading and learning about them and eventually watching videos in action. Ultimately you just install them and try out. Tiling window manager are not like an entire desktop environment and therefore not that invasive or disruptive. You can easily remove them if you don't like.

Try Niri (a linear window manager), I have tried it already for a short time on a seperate computer. It is very good! I just not got around configuring it for my main machine, yet.
And I need to test how well Xwayland works, because I need it for Steam and some games.
- I've been enjoying niri a lot as well, it's one of few scrollable tiling managers. Check out their gif to get a sense of what that's like.

just pick one don't overwhelm yourself with choices. testing out different software is part of the experience just be prepared for possible migration. currently I'm using hyprland and I'm happy with it but for Xorg/X11 i3 is a fine choice.

I went back to xmonad from Sway a while back when I realized color management wasn’t coming to Wayland any time soon.

I absolutely adore xmonad. You can do ANYTHING you dream up in it. Additionally, it helped make Haskell less intimidating for me.
I have high hopes for their Wayland port called Waymonad. But it’s a long way off.
Little known fact: xmonad is the only WM that has a formally-verified base.
I run an xmonad community here: https://infosec.pub/c/xmonad

You can pick any. I guess the way is to just pick one based on it's description or users or package availability or size and then learn to use it. And or try another one when you figure out if it has problems. Sick with the one you like the most. Or write your own.

I personally like DWM and use it as my main window manager. Caveat emptor though, the suckless devs are a bit weird. Bit of a bad smell around their politics even though they claim to be apolitical.
- I also am a fan of dwm.
  The wonderful thing about open source projects is just use the code and move on.
  One can modify it as they please if needed, but if the code has no crappy political baggage then so be it.

Well, it changes after you start to use them. With enough experience, you'll start to think that, "I don't like this feature that much, how would it be this way?", and there is probably already a WM that does it.
I started using WMs long ago but my first tiling WM was i3 as well. However configuring it to the way I like was taking a lot of time, so I was in a search for a WM that does what I like out of the box. After searching I have found bspwm. It is still my go-to WM if I use Xorg, but I moved to Wayland recently and Hyprland was the easy choice. Though currently I'm reading river's documentation and I'm thinking to switching to it when I feel ready. From what I read, it can do what I want, with enough configuring. And it seems really flexible.

Try different ones out! If you have the time at least.
Otherwise, I'd personally suggest trying out some of the more active Wayland WMs, such as Hyprland or Niri, and of course, sway which is i3 but for wayland! :)
I suggest Wayland because X11 is being dropped everywhere, so it isn't too wise to get used to an X11 WM, if you're going out of your way to learn something new in the first place 🙂🤷‍♂️

You should keep up with i3 or Sway. They will provide you with most of what you need for actually getting things done. Others you just will further yourself in an endless configuration rabbit hole

I use bspwm and I really like the unicorne philosophy of the config files (bspwm controls your windows and such, sxhkd controls keybinds, two separate programs and config files. The bspwm config file is also just a bash file so you can add anything bash related to it easily.
This said, I love the dynamic workspaces on i3 and wish bspwm could replicate them. I don't like i3 enough to switch to it purely because it's also on x, but when Nvidia gets better Wayland support I'm definitely hopping ship to sway (i3 on sway basically)... Or when I'm able to swap my 3080 ti for an and gpu at a reasonable price

Whatever you do, steer clear of Plasma Wayland right now. Polonium has a lot of issues.
- According to Brodie Robertson, there is a new krohnkite: https://www.youtube.com/watch?v=_Fw8LS3qXPg
  
  Fugg yeah thanks for the tip!. I was not there for krohnkite the first time around, but I'm here for it now.

I switched from Pop OS tiling that I had retro bolted onto stock ubuntu to Sway, massive step up and more importantly I get to keep my Ubuntu/Wayland base.
As with most add on WMs I had a bit of a learning curve sorting out the extra bits and pieces that just come stock as part of Ubuntus Gnome implementation such as a launcher (I use dmenu), a menu bar (swaybar for me), and even a lock screen (swayidle). Even doing things like wallpaper needed more effort.