I agree with all of your points. But to answer your question regarding charging.
You can buy joy con chargers, I've seen them in stores, they have like a whole stand that also charges your joycon. There are various licensed and unlicensed designs like this. Alternatively I've seen on Ali express, just a cable that splits into two, and can connect to the bottom of the joycon rail, just where the connector is, and can be plugged into a USB-a port.
Another official way to charge them is they in I think only released in Japan, as an arms 2 accessories? I may be wrong pulling this from memory and I don't play arms. They sold joycon aa battery packs. Which were joycon grips, with two aa batteries making them thicker, and also a strap on them.
Lastly Nintendo announced before the switch came out, a charging grip for the joy cons. Like the one that was included with the switch, but it also had a battery that could let you play for even longer, and charge via USB-c. I don't think this was ever released, I misunderstood and thought my release day switch would come with this product, so I was sad to see the grip that came with the switch was only a plastic holder. But I can wager a guess that some other 3. Party accessories maker has released either a licensed charging grip or an unlicensed one.
I haven't seen it, but IMO the best product for me, if I was in a situation where I wanted to use the joycons exclusively on a non switch device. I'd like to have something similar to the official joycon straps, but it had a USB-c port on them for charging.
I agree, they should have come with a charging grip. If I recall correctly it came with a non charging grip? It can't cost much more to add charging...
I was forever eyeing up the [Hori Split Pad](Hori Split Pad Pro (Black) for Nintendo Switch (Nintendo Switch) https://amzn.eu/d/7INO8wM) but it not being wireless always put me off.
I also really love the Touchpads, and would love to use the deck (or my pc) on my tv with a controller similar to the steam deck controls, have you found one like that, because I haven't.
I'd miss the charging function as you can only charge them on a switch. Also you could never attach them in case you want to handheld it for a bit. Pretty sure you can connect them, as you can use them on PC too.