I've come across PS1s with bad lasers or struggling lasers, but I've never had one develop problems after I've owned it. I guess it mostly comes down to use, the less used consoles are often in much better condition, besides the launch console which is known to have a poor quality laser assembly and will die with any regular use. The later lasers might depend on use of burned discs, or using the swap trick for both burned discs and imports as it prevents the laser from refocusing between discs. Certain games really cause a lot of stress on the lasers as well, I've heard Crash Bandicoot is hard on lasers. Really, every disc drive will eventually fail with enough use from wearing out the laser. At least it's easy to service a PS1 console. I've come across a few PS2s with similar laser issues as well, but I mostly avoided beat up looking ones and I never had one actually die on me. I just assume that modern consoles won't be as easily repairable compared to the PS1 or PS2, more difficult to solder components without specialized equipment and more difficult to replace lasers as with the Xbox 360 the drives are paired to the specific console they come with. Overheating issues will become more common with modern consoles as components age.
A friend of mine bought a backwards compatible PS3, and it died within a month of use. She ended up replacing it with a later slim model instead.