Sure, kind of.

So Steam and Etsy themselves trend toward some amount of centralization, but in the case of Stream for example you have Playstation, Microsoft's platform, Stadia (soon to be cancelled I'm sure), Switch, Epic game store, iOS, and others. They aren't all exactly 1-1 comparable but I think that's ok. Frankly, you can get games from a lot of sources. You might say you can't get an indy title from one of these sources that you can on Steam, but you can't buy Halo on Playstation either - that doesn't make things centralized. It's a very competitive market.

In the case of Etsy I think you're a little more right, but there's no reason that has to continue to be that way.