Some sort of service that you pay to keep storage space to which you periodically (probably automatically) upload the contents of your own computers to, such that you can then download everything later if it all goes horribly wrong. I have a macbook and windows machine I realise I would be truly devastated if I lost all the files on, so I figure this sort of thing makes sense. Unfortunately every backup service I can find looks...

extremely sketchy? So I'm hoping somebody here will have experience with backups and will be able to say like "no Backblaze is actually good even though it looks like That" or something. I'm happy with something techy (like buying general purpose cloud storage and running a free program that interfaces with it) if it ends up being cheaper, and all the storage I want to back up adds up to to a bit under 3TB.