It is not just about trust.. on an oss project I expect other people to have already read the source code when I can't. People with no incentive to lie or hide whatever they find
With that said, i'd never pay $5/m these days for something unless is had very good value to me and obvious ongoing costs i'm using (servers/etc) for the dev/company. Those costs would need to be clear though, not just "we chose to run some servers so that we'd have features which justified subscriptions"
I would however, pay for upgrades - ie the licensing model employed by JetBrains/etc. Which can come out to $5/m (or yearly purchases, etc), or w/e, but most importantly the software keeps working if you decide to cancel.
edit: Also i'm on Linux. Looks like i can't buy it anyway haha
But that makes OSS more complicated - people usually don't pay for something they can clone & build themselves.
BTW: Linux and Windows will definitely happen, I just didn't have time yet. Sorry, it's a lot of work and time so I had to pick macos first, and even that alone is a lot of testing on different configurations.
Ideally your app would be all FOSS components and i pay for the glue to tie it all together, but i've seen that become too easy to knock-off. Depends on the app of course. Still, FOSSing parts can do a fair amount of good will to the FOSS crowd, imo.