There definitely will come a day when it's going to be a rare thing to be able to experience a disc-based console the way it really was. Eventually we'll all be using something like the Dreamcast's flash loader and bypassing the drives on every system, and the drives will all die without us even knowing in a lot of cases. I'll bet at least one or two of the CD-based systems I have boxed up right now don't work anymore, unbeknownst to me. That's what happened with my Dreamcast; I babied that thing, kept it boxed up for a while, took it out again and it didn't work.
From my own experience, the only two optical disc systems I've definitely had go bad are my Dreamcast and my launch PS3. But in the PS3's case, it's not the drive that died; I had the common issue with the CPU coming unsoldered or whatever. (I probably could have fixed it now but didn't have the skills at the time.) The Dreamcast, though, would no longer read discs.
I do know from searching around to buy one that PSX's seem to have a horrendous laser failure rate; it's actually hard to find a fully working one already. (Some seem to read one kind of disc but not another, so you can find partially working ones more easily.) Ditto for original Sega CD's, although mine was working when I sold it (I should have kept it; I regret that whenever I think about it).
I know that original PS2's and Xbox's have a bad reputation, but all of mine still work (1 JP and 1 US PS2, 1 Xbox), as far as I know.
My second revision PS1 (still has serial port but no RCA ports) still worked last time I fired it up, but it's been a while.