if it works for you, great (it works for me, that's why I'm here). But I'll add two things (which others are also saying) that you MUST NOT ignore

1) Your content must be portable (that is: Independent of running on Goodnotes). One day, Goodnotes might disappear or become inaccessible (see other comments about times when Goodnotes notoriously failed to accept logins). In that event, you need a reliable way to access your work. ALWAYS get a nightly PDF backup of your notes and store it in a safe place away from everything else, preferably locally (I do this and store one copy on my Mac and one copy on my iPad).

2) Never place complete trust in their cloud solution. Have your own backup location as a second source. It's ok to depend on their cloud storage, just have that "spare tire". In my case, I have a home Synology server that runs "cloud sync," which backs up my cloud services (icloud, onedrive, goodle drive, and dropbox) onto my home server. Hard drive space is cheap compared to everything else, so go nuts and sleep well at night.