Gemini is what happens when people are so traumatized by years of the web platform being horrifying, they react to the other extreme and build something so bare-bones (with a policy of not allowing any kind of extension) that it will never become a general-purpose solution that most people will adopt.
And that's fine; if some people want their own sandbox so they can avoid the horrors of the WWW as much as possible, more power to them.
But let's not pretend this is going to be come a widely-used platform where people are going to be able to do but a small fraction of the things they can do on the web. Again: that's fine! But it can't and won't replace the web.