ICloud. Although, it doesn’t really make any sense if you’re not already somewhat in the “Apple ecosystem”.
Last I checked it’s e2e encrypted.
A more general suggestion is probably ProtonDrive or NordLocker. I’ve used both of them in the past but found them slow and clunky, tbf it was some time ago and they were still in beta.
Can’t believe I forgot the most important step. Thanks for the addition dude :)