You may own the keys but the non-profit The Tor Project owns the network. And when they decide to shut it down your "ownership" of the domain keys doesn't matter in the slightest. You might think this is a silly scenario but actually it happened in 2021/2022 when the tor project unilaterally decided to kill the entire Torv2 network and all domains were made inoperable. All links between sites, everything that made .onion a web, was lost.

The Tor Project does this whenever they feel that there's a security issue. It will happen again.

As someone that spent 10 years building completely legal community sites on the .onion network with the delusion of ownship it really hurt me. I'm never using .onion again. It is not a place to try to build communities. It is only for people that need 'security' as a highest priority and don't care if everything gets wiped out.