The most popular Docker image for Caddy, for example, should soon (if it's not already) be compiled from source, rather than from the build server. That means it will remain free to use, and I personally don't have to make a single change.
If this has impacted you negatively to the point where setting up nginx is an easier option, well - that's the beauty of choice!
Personally for me Caddy is (was) good because of how easy it is to set it up.