Mostly by checking teardowns and reviews - that’s the one thing Amazon reviews are still good for - check them, especially the ones with a more negative sentiment and form an opinion based on that…

Also, certain brands more or less got similar issues over all the product ranges, for example power supplies giving up on Hisense TVs, compressors on certain fridge manufacturers etc - there are patterns to look out for - especially when the product has been on the market for some time.

Especially when this changes.

My first Ecovacs robot vacuum lasted 5 years, the replacement died in months and I've replaced that.

Its a complete pain to get open, and the way its wired makes it a complete pain to get around to try and repair.

Don’t tell me they’ve all three been Ecovacs?

The two times I had to open my Roborock S5 (once because our cat decided to vomit when the robo cleaned up and once to replace a broken Lidar motor) I actually was very delighted by its thoughtful design - basically none of what you describe, everything was very modular.

I mean, of course, you’re right - a different model can and probably will be designed differently - but that’s what teardowns are there for - fool me once, check the next time beforehand.