I would be more worried about copycats. When you share your success, other developers want to have it too.
Even if you believe you are for the long run you lose money in the short term because of your ego.
I personally pay for Plausible because I like how much they share. They frequently pop up in discussion on HN, and I think their openness drives a lot of that mindshare among the crowd here.
If it's a service I care about, I don't want to be on the free tier because I want a mutually beneficial relationship with my service provider. It's cheaper for me to pay a few hundred dollars per year than to have to scramble and switch platforms when my vendor folds or drops their free tier.
I've been a paying customer for over 2 years and their transparency and overall a strong "sharing" culture played a big role. It's just easier to trust.
We are building windmill.dev this way and fully open-source, I'm less worried about copy-cats than about the project not taking off because of too much friction.
But Plausible was MIT licensed until 2020, so maybe a clone of early Plausible?
A lot of relatively new analytics services tend to have similar looking frontends these days I've noticed though.
A good rule of thumb: if you think something is original, chances are it’s because you’re just not very familiar with the space.
Ultimately, none of this matters. The goal of a product should be to help customers achieve the outcomes they want, not create something original.
Please notice that although they recommend docker for self hosting, it is very easy to self host an a bare RHEL server (you need to be a little familiar with Elixir though but not so much, you can take a peek at the docker entrypoint scripts to see what's going on) ; I'm doing exactly that for some months now and I'm happy with the results.