3 months ago I upgraded from my OnePlus 3T to a second hand OnePlus 7T. I bought the 3T when it came out, around early 2018 My reasons for the upgrade where mainly the camera which did no longer work at all. I did replace the camera module 2 years ago and probably did not do a great job though. I never had issues with broken or cracked screens so far and always wonder why as this seems to be a widely spread issue. So I guess the user plays a big role in longevity aspects.