I've had password login enabled for decades on my home server, not even fail2ban. But I do have an "AllowUsers" list with three non-cryptic user names. (None of them are my domain name, but nice try.)

Last month I had 250k failed password attempts. If I had a "weak" password of 6 random letters (I don't), and all 250k had guessed a valid username (only 23 managed that), that would give... uh, one expected success every 70 years?

That sounds risky actually. So don't expose a "root" user with a 6-letter password. Add two more letters and it is 40k years. Or use a strong password and forget about those random attempts.

I wonder about:

- silently compromised systems, active but unknown

- VPS provider doing security behind your back

I'd be worried about this too. Like there must be AI bots that "try the doors" on known exploits all over the internet, and once inside just do nothing but take a look around and give themselves access for the future. Maybe they become a botnet someday, but maybe the agent never saw the server doing anything of value worth waking up its master for— running a crypto wallet, a shard of a database with a "payments" table, an instance of a password manager like Vault, or who knows what else might get flagged as interesting.

Security is way more nuanced than "hey look I left my door open and nothing happened!". You are suggesting, perhaps inadvertently, a very dangerous thing.