If starting anew Thread is probably a better bet. Such as the Eve smart plug.
But with both zigbee/thread the problem is shifted towards the gateway instead so you'll have to do it yourself / pick one tu trust there. But here I think/hope Thread is going to have better interoperability.
And if you don’t want to deal with the hub potentially being your next issue, you can always throw home assistant on a computer / raspberry pi / whatever and control them locally. If you want remote access when you’re off your network, it’s up to you to figure out how to securely get the bits from your phone to your home assistant server.