Perhaps it's worth mentioning XCA [1] at this point. It's a GUI based on openssl that provides an intuitive UI for managing keys, certs (root CA, intermediate CA, server and client) and CSR. It existed before acme and mkcert. What I liked in XCA was that it made it easy to review all parameters related to the operations it managed.
[1] https://hohnstaedt.de/xca/index.php