A password manager seems both necessary and obvious. Besides allowing you to use secure passwords with ease, it also allows you to enter passwords without typing them (avoiding cameras capturing what you type).
A SIM attack is just one way to bypass what many sites pass off as two factor authentication (2FA).
Anyone who gets into your email is going to bypass most of them. Anyone who gets into your phone (such as with a SIM attack) is going to get into the validation codes texted to your phone. Anyone who gets into your computer can also get them, if your computer is also receiving text messages.
If your bank offers sending you you login validation codes by text, email, or their app, turn off text and email and just use the app.
Time-based one-time passwords (TOTP), generated by a device, is a better choice, but of course is vulnerable to the compromise or loss of the device or whatever you use to read it. (IIRC, the biggest supplier of those had a vulnerability for all previous devices in the last year.) I would advise against using TOTP from your password manager or even from a device that has your password manager on it.
BUT... Password managers are vulnerable to anything that captures you typing your password to it. (keyloggers or cameras) There was a significant incident recently that started with an privileged user getting a keylogger on a personal computer. The bad actors captured the password to his password manager, then used that to get into his work systems.
A suggestion: For your critical passwords, do not store the entire password in your password manager. Do something like having a suffix that you add to the stored password (or, alternatively, add a few characters to your stored password, that you delete after the password is filled in.)
I also am a believer in the use of long, word-based passwords. (Not "beam-me-up-scotty" but random words, such as DOCKHAND-socrates-finn-frizz). These are perhaps easier to type and certainly easier to verbally pass to someone else, or to remember from the time you see it to the time you type it. I expect most password managers offer the ability to choose these. My password manager uses a dictionary of 30,000 words, so there are (30,000)^4 = 8.1x10^17 4-word passwords. That is equivalent to truly random 9-character passwords such as NL9gC-aDE. A 5-word password (2.4x10^22) is better than a truly random 11-character password.
Beware of using Leet-speak passwords (P@55w0rd) as attacking that is built into all password cracking tools. The crackers also have every typing pattern password you can imagine (1qaz@WSX). If you insist upon coming up with your own password, try to make it one that no one in the world would have EVER used. If someone in Portugal used it 5 years ago, it very well could be in the dictionaries of previously captured passwords. I quickly found a list of 8.4 billion such passwords. These would be checked first.
How fast can passwords be cracked? Online attacks (attempting to login over the net) are usually throttled by the server's speed of checking the password, or intentional delays in that process. Offline attacks (where the bad actor has a stolen copy of a set of hashes used to authenticate users) can run at amazing speeds. Basically, the system guesses passwords very, very quickly. An
M3 MacBook can attack Mac 10.6 password hashes at a rate of 2.3 billion tests per second (so it would cover that 8.4 billion captured passwords in 4 seconds, and start testing variants). It can attack captured WPA-2 (wifi) packets at 145,000 guesses/second to discover the WPA2-PSK password. Not only can bad guys have big rigs with lots of even faster GPUs, but they also post the hashes publicly for others to use their rigs on them.
Edit: If you use a PIN or password to unlock your laptop/tablet/phone, you need to expect that whoever steals that device has recorded a video of you entering that password. (which, by the way, means a long password is not much better than a shorter one). It is much better to use the face recognition technology (I don't know about others, but Apple's seems pretty solid against someone forging your face). From the little I know about fingerprint readers, I'd be wary of them, but I haven't noticed any common attacks of, say, 3-d printing fingertips from a fingerprint or a picture of a finger tip. Eventually, we'll get to where we carry one device to unlock the other devices. That device IS the digital you, so it needs to be protected. (Something like the Apple Watch could be that, as it knows when it leaves your wrist and shuts down. But so far, it doesn't seem there yet. And it isn't sufficiently protected from someone entering your unlock PIN.)