Well, you are technically correct. That would've made it easier for me. But I see a few problems with that:
How are you gonna make sure people start doing this?
And even more important: If people start doing this, it might actually harm the network IMHO.
I personally knew that something like Lemmy exists at all because I saw multiple people on Reddit recommending it as an alternative to Reddit. Often enough that I was able to remember this after some time.
Now if people recommended programming.dev in one sub, literature.cafe in another and discuss.online in a third - there is no way I would've remembered any of it and most likely wouldn't know that it belongs to the same network. Looking at them individually emphasizes the feeling that those are some ultra niche little sites with hardly any users on them.
Just my gut feeling, anyway.
I've never noticed until now that Zuckerberg looks like a giraffe.