The PS3, be it the early PHATs or even the super slims were technically amazing machines but, at least in the beginning, they still were way to expensive for the reduced quality in most cross party titles compared to the 360. Was probably a no-brainer upgrade though, if you could sell your PS2 to replace it with a brand spanking new PS3 without losing access to your games.

Also, the amazing first party titles Sony put out over the years (that actually took advantage of the PS3's over-designed processor) make it worth buying even today, as you can get it for less than 50€ in good condition and it's easily jailbreakable.

Just maybe don't sell your first born for one that is backward compatible with PS2 today. Just buy a used PS2 as well (most of them are jailbreakable just as easily) or just emulate it.