I used to like Samsung for their display tech. Once owned a 20" monitor that lasted some 15y while seeing daily use. Which degraded gracefully at the end.

Everything Samsung I've owned since then, has been... mediocre. Just random hardware parts crapping out that should have lasted longer (and like you, not worth the cost of repair).

I think it's more a sign of the times, really. Build quality isn't what it used to be. As cheap & unsupported as manufacturers can get away with. Software is no exception.

In your case, I'd have a look at LineageOS & friends. Am using this myself. A good way to keep using older phones (if hw is still ok) long after vendor ships updates.