If I am being a bit pedantic. Yes you can still download your old games, but they will likely be different from the original release. Grand Theft Auto games are known for dropping songs from the soundtrack due to licensing.

If you have Vice City on DVD and install it you can still enjoy Michael Jackson. Not with the Steam version.

As much as I like Steam and dislike Sony (quite a bit in both cases), I will point out that while you can still download every single thing you've bought on Steam, there's no guarantee that it will run on a modern PC. A handful of my past Steam purchases don't. Consoles still hold the advantage of being a tightly defined target platform and a game written targeting a console is compatible with it indefinitely.

You can still download games for PS3 and Vita after they stop selling them. It’s no different from how Steam no longer sells some titles it used to.