I've typically seen most 10gig kit to need a lot of cooling (either heatsinks or active fans), not something I'd be too happy about dealing with. Also there's like only the homelab enthusiast that needs 10gig. The rest of user can potter along fine on 1/2.5gig as we're not slinging ZFS snapshots about the place.
Tl;Dr 1/2.5gig works for consumers needs, 10gig is not price competitive for our needs.
> If it was available, there would be apps to use it.
To an extent, since the inverse is also true: there is as of yet no market demand for such large amounts of bandwidth either.
Once popular apps/usecases with heavy bandwidth requirements see wide adoption (at first limited to specialty high bandwidth networks), we will start seeing growth in the consumer bandwidth space.
Tl;Dr 1/2.5gig works for consumers needs, 10gig is not price competitive for our needs.