You lose functionality though, like being able to check doors etc. remotely.
I trust Apple and I trust Homekit so I'm not too concerned with that.
You don't. That's what VPNs are for.
If it's an end-to-end VPN, it's doubtful most of these devices have the power to run a client.
[1] https://news.ycombinator.com/item?id=16847716
You lose functionality though, like being able to check doors etc. remotely.
I trust Apple and I trust Homekit so I'm not too concerned with that.