It is truly upsetting to see how few people use password managers. I have witnessed people who always use the same password (and even tell me what it is), people who try to login to accounts but constantly can't remember which credentials they used, people who store all of their passwords on a text file on their desktop, people who use a password manager but store the master password on Discord, entire tech sectors in companies locked to LastPass, and so much more. One person even told me they were upset that websites wouldn't tell you password requirements after you create your account, and so they screenshot the requirements every time so they could remember which characters to add to their reused password.
Use a password manager. Whatever solution you think you can come up with is most likely not secure. Computers store a lot of temporary files in places you might not even know how to check, so don't just stick it in a text file. Use a properly made password manager, such as Bitwarden or KeePassXC. They're not going to steal your passwords. Store your master password in a safe place or use a passphrase that you can remember. Even using your browser's password storage is better than nothing. Don't reuse passwords, use long randomly generated ones.
It's free, it's convenient, it takes a few minutes to set up, and its a massive boost in security. No needing to remember passwords. No needing to come up with new passwords. No manually typing passwords. I know I'm preaching to the choir, but if even one of you decides to use a password manager after this then it's an easy win.
Please, don't wait. If you aren't using a password manager right now, take a few minutes. You'll thank yourself later.
so is it bad to store my 2FA backup codes as notes in those same login's bitwarden entries?
I do this too. I would need them if I lost my phone, so bitwarden/keepass is a good place for them to be.
I think it is less secure though since someone who somehow has the unencrypted vault without your 2FA device could get in with the codes - but if someone cracks my master password I'm screwed in a whole bunch of ways so I'm not sure it matters too much at that point.
It depends on your threat model. It does mostly reduce the benefit from 2FA, but you are probably still very safe if you use a random password per site. I mostly use 2FA when forced (other than a few high-value accounts) so I don't worry about it. For most people having a random password which is auto-filled so that you don't type it into the wrong site is more than sufficient to keep themselves secure.