My eSIM is tied to my phone, phones these days have encryption, so all I need to do is set a lockscreen password then a thief cannot access any of my data.
WRONG
At least in Android: You can just use some button combo (just look up "[Phone model] hard reset") to get into the recovery menu and wipe all data, then reboot, and the eSIM is still there!
(Caveat to this: If you happen to have a Google account, it would force a FRP lock, and that would stop access, but most of fediverse does not like those type of online accounts, so: without a SIM PIN and without FRP locks, the eSIM is accessible to a thief)
Now the thief has your bank 2FA Codes!
TLDR: Set a pin on your SIM cards, even if it's an eSIM (but especially if you use physical SIM cards)
(Curious: Does anyone actually use SIM PINs or do I just have a lot of paranoid regarding tech and potential hacks/exploits)
On android, the setting is in Settings>Security>More Security
Yes
The fact that it can only be attempted three times, after which a much longer PUK code you from your service provider must be used to restore funtionality to the SIM. It also has limited attempts, after which the SIM is locked forever.
Not sure how that works cryptographically, or how robust a physical SIM is against tampering.