The current audience for Lemmy/Fediverse is a niche group.
A niche group who is here because capital destroyed other platforms we loved.
I don't think my statement is untrue but I also don't think it will remain true for much longer for exactly the reasons you put forward.
edit: @LEVI@feddit.org
I have a netgear router that isn't even that old and it doesn't have gigabit ports.
even though I was able to throw openwrt on there to mess around with it's still e-waste