First and foremost, you should keep your devices secure. Lock them when not in use, and do not let other people use your devices. For added security, you can use various available solutions for whole-drive encryption (e.g., Bitlocker, VeraCrypt, etc.).
Second, there is absolutely no need to use a random 75-character password.
Your master password should be a a randomly generated passphrase, consisting of a string of words that have been randomly selected from a list of 5000 or more words (using a passphrase generator). Even using a passphrase of only 4 random words should provide sufficient security for the vast majority of users. For added security, some users prefer to use passphrases consisting of 5-7 words. These passphrases can be readily memorized with a little bit of practice, they are easy to type, and they provide all the security that you need for your vault encryption.
Random passphrases with words selected from a 7776-word diceware wordlist (such as the EFF wordlist that is used by Bitwarden’s passphrase generator) provide 13 bits of entropy per word, so you would get 52 bits of entropy with only 4 words, and 90 bits of entropy with 7 words. There should be no need for higher master password entropy unless you are a highly targeted “Enemy of the State”.