After mullvad disabled port forwarding, I switched to AirVPN and it works fine. I trust it slightly less than Mullvad but I'm avoiding copyright trolls, not three letter agencies.
Not to sound snarky, because this is a genuine question, but what does that even mean? Unless you’ve been brazenly selling child porn over the VPN and been getting away with it for years, I don’t really know how you would establish a VPN is trustworthy vs you just haven’t been targeted for your minor torrenting, or whatever.
Well, it's been operating for a while now without any major outages, no issues with torrents, exposes way more "techie" features than any other VPN I've used (customizable port forwarding, dynamic dns and customizable subdomain names on those ports, different device profiles, customizable dns filtering lists, all sorts of stat graphs for their various nodes, script generators for openvpn which allow choosing all sorts of protocol related details) works fine for bypassing region locks on the obscure music sites I care about and they've been completely fine with an anonymous Monero payment (well, as anonymous as you can be to what is effectively your ISP).
They have a good record of responding to various restrictive legislation around the world (eg pulling out of Italy after they passed an overly broad 'anti-piracy' law) and also haven't had any open scandals. That's about as good as I can really expect considering that I'm mostly just not interested in my local ISP knowing what I'm up to, and am not doing anything hugely illegal or pirating at a large scale.
For reference, the VPN I used before then offered no real controls besides a limited country selection and a randomly assigned port forward. It was bought up by a company owned by a guy known for running scams, after which I switched out. Now having seen all the customization I was missing out on, I can't really go back to a simpler VPN.