Yes - they're already on my computer, so any full-disk backup service will back them up by default. There's an option to purge them from disk and download from iCloud on demand, but you don't need to use it: https://support.apple.com/en-us/111762
It's different on mobile (iOS/Android) where individual apps need special support for cloud providers. On a mac everything is just a file for most apps, so all the cloud providers work by default.