How would you set up a decent backup setup?

IvanOpinion

Of course. My main (paid for) cloud storage is pCloud. I also use the free storage from Sync and IceDrive for specific purposes. pCloud has been my cloud storage preference since 2016 (after SugarSync and then Cubby changed their business models). It just runs in the background totally transparently doing what it is meant to.

During that time it has worked absolutely flawlessly, including when my Seagate HDD crapped out on me. I added a new disk and let it sort everything out for me overnight, I lost nothing. It also syncs documents/photos/videos on my  phone and other devices that I have it installed on, and makes files available across devices. Not forgetting the multiple versions of documents that it holds allowing me to rollback to any given date in the last 6 months. 

In fact the only issue I have had is that if you try renaming a file while it is syncing it can sometimes reject the name change. This behaviour can be turned off but since it is nothing more than a minor irritant I do not bother. 

JustAnotherSaver

The only 'cloud' thing that I use is for my (Android - Galaxy S10) phone backup but then that's only because I don't really know how to or if you can do a 'proper' backup.

When I was with iOS, I'd plug the phone in to iTunes on my Windows PC and just select backup. I could do the same in iMazing which I found to be more flexible than iTunes.

Through poor experience, I learned to do this 3 times - create 3 individual backups with the above program which SHOULD eliminate corrupt backups or at least reduce the chances massively. These would be stored on my PC hard drive.

That's the thing I loved about the iPhone - the backup was an image of the phone. Get a new iPhone, restore from backup & it was like your old phone, just in a newer shell.

I've restored from the cloud on my Android and it restored many things but not everything. It wasn't a total phone image.

If I had the option to do that on the PC then that would be my main backup. As it is I accept this cloud backup though it's not my favourite.