Random mixtures of letters and numbers is a complete nightmare (maybe unless you can copy and paste it)
Copy and paste is what I do.
I have a text file with hundreds of sets of IDs, email addresses and passwords, a different set for every entity I deal with. For banks and sellers I must obviously use my real name, and for websites where it would not matter (like hobby forums) I use the same password. I am with an email provider (several in fact) that allows an unlimited number of email addresses and I now have hundreds of them. This file is encrypted with a master password and stored on two different devices, and I have different files for finance and non-finance. I open the file if I need to look up an ID and password and then I close it again, but I can remember the ones that use my common low security password. I see no need to pay someone else to host such a file.
If someone discovered my password for this forum for example and logged in pretending to be me, it would not be the end of the world; there is nothing much in here that links me to anything else beyond what is in the text of my comments, and I am quite careful with that. They could place me in a vague geographical area but even so Google (for example, by the ads they show me) thinks I live 200 miles from where I do, and that I want to buy an industrial air compressor. I don't, but I am not going to correct them.