Main reason is that if you don’t already have the right key, VPN doesn’t even respond, it’s just a black hole where all packets get dropped. SSH on the other hand will respond whether or not you have a password or a key, which lets the attacker know that there’s something there listening.
That’s not to say SSH is insecure, I think it’s fine to expose once you take some basic steps to lock it down, just answering the question.
Some people move the port to a nonstandard one, but that only helps with automated scanners not determined attackers.
While true, cleaning up your logs such that you can actually see a determined attacker rather than it just getting buried in the noise is still worthwhile.
Reverse proxy + DNS-challenge wildcard cert for your domain. The end. Super easy to set up and zero maintenance. Adding a new service is just a couple clicks in your reverse proxy and you’re done.
Lots of ways to get around that without having to go the route of burning a hundred blu-rays with complicated (and risky) archive splitting and merging. Just a handful of external HDDs that you “zfs send” to and cycle on some regular schedule would handle that. So buy 3 drives, backup your data to all 3 of them, then unplug 2 and put them somewhere safe (desk at work, friend or family member’s house, etc.). Continue backing up to the one you keep local for the next ~month and then rotate the drives. So at any given time you have a on-site copy that’s up-to-date, and two off-site copies that are no more than 1 and 2 months old respectively. Immune to ransomware, accidental deletion, fire, flood, etc. and super easy to maintain and restore from.