Business-grade backups can be a very complex area - realistically though, for most home users, Cloud services are probabaly the way to go now. I know there will be a lot of people quick to point out that Cloud services are not backups - but this is only partly true.
It is true that Cloud services were primarily designed are a way to SYNCHRONISE data, not back it up. This means that all changes, including errors, file corruption, and deletion are also replicated across the Cloud copies.
However, saying that this makes it ineffective as a backup ignores a key feature: Versioning. Cloud storage that offers strong file and folder versioning can roll back these changes fairly easily, effectively making them a viable and simple to use iterative backup option.
Personally, I already subscribe to Microsoft 365 for the Apps, and this comes with 1TB of Cloud storage included with decent file versioning, so I use this for my personal data, and iCloud for photos and settings.
I would not rely on a Cloud-only system for business-critical servers, for example - but realistically, how complex does a home backup solution actually need to be? Cloud services can be relatively effective, simple to use, cheap and are always running in the background so backups are never missed.
A few caveats though:
If you have very large quantities of data, paying for additional Cloud storage can get expensive.
If you are very concerned about privacy, Cloud storage does put your data in the hands of a third-party company (albeit encrypted).
If you have exceptionally slow internet in your area, Cloud storage may not be practical.