Cat7 is not a recognized standard by TIA/EIA, but there apparently is an ISO standard for it. Also, cat7 doesn't use RJ-45 connectors so it's not backwards compatible with older gear.
Cat6a is probably the sweet spot for home/office/etc structural cabling. It's not much more expensive than Cat6 (or Cat5e in case people are still putting that up), and has more than enough legroom.
Cat Cat6a is a pain to retrofit as it's stiffer and thicker than Cat6 in most cases. It's also more expensive (less so than before, but the delta is still there)
If each run is <55m then Cat6 can still do 10Gbps.
Cat6a is probably the sweet spot for home/office/etc structural cabling. It's not much more expensive than Cat6 (or Cat5e in case people are still putting that up), and has more than enough legroom.