Can you own gold without owning gold? Not sarcasm; think about all the ways people "own" things.

There are some unique properties to Bitcoin which allows for clever things like Lightning, but every scaling layer will either introduce trust or complexity or both, and reduce security (more code, more attack vectors and more potential bugs).

For everyone to own, really own, Bitcoin would require a different consensus mechanism, which would degrade the security or increase the trust required. Scaling the base layer. It's a trade-off most other cryptocurrencies make.