A while back, I tried submitting a patch to OpenSSL. It was a 3-line change (IIRC) related to the build process - in a particular esoteric setup, the build failed. Got literally zero replies regarding the issue on the mailing list, their IRC channel and on my/their github pull request.
I'd love to contribute more often to other OSS projects. But this behavior is more common than not.
I've also submitted patches to OpenSSL and been entirely ignored[1]. The latest of which strictly improved testing, documentation and included a detailed study and write-up of actual bugs in OpenSSL and downstream code[2].
My conclusion was that the OpenSSL project is not interested in external contributions.
This has not been my experience. I've contributed to many different projects, large and small (chpasswd, sendmail, apache, git, gerrit, openconnect, homebrew, msmtp, textmate, ...) and never had trouble getting a patch accepted.
Those projects don't suck, though. When projects (continue to) suck, it's usually because their maintainers suck. When maintainers suck, it's hard to get patches in.
I'd love to contribute more often to other OSS projects. But this behavior is more common than not.