Yeah, no.
A short story that happened some months ago. My sister, a teacher, called me in full panic mode. All her school related documents, which she stores in iCloud, were gone. Her iCloud drive was empty.
So I told her to look into her backup. Which she didn't have
Luckily for her, Apple offers some sort of data recovery on the icloud website and I was able to restore (most) of the files. One of her kids managed to **** around in the icloud app on her iPhone...
One place is not good enough for valuable data. You absolutely need a backup of these files for that one time disaster strikes. You'll probably never need it of course. I, for example, never ever lost a hard drive before it was too late, but do I want to take any chances? Hell no.
Btw. Setting up my work computer definitely takes a while. And it needs my attention. A full backup is a press of a button and involves some time I can invest elsewhere. That's a huge difference.