Maybe this used to be a big problem

They're a plague on gardens. It might be a metaphorical relic of an age before modern pesticides.
Edit: Sorry, I know this isn't funny, but I've also wondered about this odd phenomenon, too, and this just occurred to me.
- There's a documentary that posits the monks who were tasked with writting all the shit down had personal battles with snails who'd eat the manuscripts. I guess the books/pages were shellacked with stuff that would attract them. The monks then turned it into a meme and drew them in the margins and depicting fights like they were dragons.
- Exactly. Any gardener knows snails are deadly. Even in our age!

The snails are Normans aren’t they?
- We don't know. It was supposed to be funny though, so honestly probably not anything too deep or specific.
  The theory I tend to believe is that it started as a commentary on the endless battle against garden pests, and just became a genuine meme beyond that.
  
  To be fair, giant African land snails are about this size IRL.
  Maybe it's a combo of a few shells traded around plus the garden pest meme to make very snail seem like a murderous asshat.

Look at that S Car go 🚘
- I'll take the S Club 7 while we're at it

I cannot find the video I watched on it years ago, but this video is pretty good, and goes over the same general theory.
Aside from this, though, can we go back to illuminated manuscripts? I'm not talking hand drawn or anything, but can we get fun little drawings all over the borders of our books? Be they serious dramas or light hearted comedies? Who wouldn't prefer to read an illuminated copy of Witness for the Prosecution, with little barristers stalwartly defending their clients to fat cat be-robed judges in the margins? The little people don't necessarily have to be connected to the written work, either. They could just be doing things. Laying eggs, fighting snails, riding dragons, shooting targets, whatever.
I'm not talking about picture books, I don't need full page artwork showing the story. Just little doodles the author approved all around the margins. But would be awesome!
- The art of the manuscript has really fallen. Published books nowadays are not as good as they used to be (in terms of quality, not just content). Most 'crafted' things, really - textiles, books, furniture... everything has been discarded in favor of cheap, low-quality nonsense that breaks or falls apart.
  
  As a crafter, I can't count how many times I've seen decorations for sale in stores and thought, "Wow, they're charging that much for this flimsy thing? It looks like it would rip before it's even taken out of the package. I can make this at home for a fraction of this cost, and out of stronger materials." Seriously, people are getting ripped off big time when all they want is some pretty holiday decor.