My current folding (flip) screen is still working after 3 years. My prior folding (flip) phone also lasted 3 years before I had to replace it because I dropped it and broke the camera. The screen is still fine on that phone though.

My current flip does have a wear mark at the fold seam on the screen, but that was my fault for using it for over an hour in -22°F outdoor weather, then promptly folding it and putting it back in my pocket out of habit. I don’t recommend doing that. However, the folding screen is fully functional and you can only see the mark on the screen when its off or if you hold it at a specific reflective angle. When the screen is one and you’re reading on it, its very hard to see the mark. Its not nearly bad enough for me to replace the phone.