Previously I was using only the photo apps LrC and PS, but have recently upgraded to get all apps plus 100GB storage. I have started using InDesign too.
What I'm looking for is an option to make sure all my projects are backed up in that storage.
I'm not inclined to migrate to Lightroom (from Classic) as I have two very large catalogs and I am not confident the migration will be successful. I would also like my InDesign projects to be backed up.
Namely, if my HD or external HD failed, I'd have backups.
I read somewhere about a sync option in InDesign but I can't for the life of me find it anywhere.
It's also a shame that Lightroom only allows me to sync one catalog at a time.
I'm aware that I can drag and drop files to be backed up in cloud storage, but is there not a more seamless and concise way of having (cloud) backups of all my projects?
adobe cc is not intended for (and does not do a good job of) backing up your files. it's intended for file sharing with collaborators and for sharing your files across your cc-enabled devices.
as you try to do, what seems to you to be reasonable things, you're going to get more and more frustrated. for file backups, use a cloud service designed for that. and then don't trust it. you should have another backup (eg, removable hard drive) for important files.