I’ve got a 3rd gen too, though I rarely use it. It’s in a spare room we rarely go in any more. The remote for the 3rd gen still works though. Think it’s the touchpad on the 4th gen Siri remote that makes the thing less rugged.
I definitely think the 4th gen Siri remotes were broken because of abuse we did. Like the one we keep on the kitchen table probably got food on it. The one we keep by the couch on the living room, someone probably sat on it, more than once. But no more than we abuse every other remote that I’ve owned for my entire life.
And I didn’t realize there were people complaining the 4th gen remotes either. Till I thought about maybe replacing it with a 3rd party remote instead of paying the $60 for a new one. And I do searches and in user reviews there are plenty of people complaining about the same thing.