I don’t use OpenPGP for email. In the few cases I used OpenPGP for email, the contacts I communicated with made mistakes that leaked the contents of emails. I’d estimate the success rate of my OpenPGP email use as 40% inspite of not making a single mistake myself. OpenPGP email is extremely too prone to failure. Purpose-built end-to-end encryption like Signal should be used instead for secure communication.
However I still use GnuPG to encrypt, decrypt, sign and verify data, particularly downloaded software. Thus I still worry about GnuPG’s and OpenPGP’s vulnerabilities. I should consider switching to Sequoia PGP, age/minisign etc but I haven’tyet.
Aside from end-to-end encryption, one major pro of Proton to Proton and Tuta to Tuta that I suspect exists is those emails don’t leave their servers. Is that correct? But this is not thanks to OpenPGP anyway.
FYI GnuPG stopped following OpenPGP (standard, website), and now follows the fork called LibrePGP (standard, website). I made a post containing a brief background of OpenPGP vs LibrePGP here.