What backup you want, depends in what/how you want to restore. So lets start with that:
I suggest that macOS is best restored by getting it from Apple at the start of a disaster recovery. So I will ignore your wanting to backup the OS as it is not needed for restoration.
But you might want to restore all of apps, your data, and settings (for both macOS and apps). In that case, the answer is No. You can't recover everything directly from any cloud backup service. You can only do that from a local backup where the local backup might be on a directly attached disk, another Mac, or a NAS. Products to do that include Time Machine and Carbon Copy Cloner.
A local backup is the primary mitigation strategy for a local disaster, particularly hardware or software failure. And can provide full restoration.
A cloud backup is a recognised mitigation strategy for more serious (but more unlikely) disasters - ransomware, theft, fire, etc. For such disasters you might be prepared to accept that recovery will need download and reinstall of apps and some loss of settings. Of course, this will only be possible after you have purchased replacement hardware (and possibly somewhere to live). But what you would most want to recover is your irreplaceable data (documents, photos and so on).
There can be times when the cloud backup is helpful for restoring specific data, but I suggest that is not its main purpose.
If you still want to backup everything to the cloud (apps, settings and data), I prefer Arq over Backblaze or iDrive. But I would only use my Arq backup to restore all my data plus a few specific settings and configuration files. And that restoration would be after having a replacement Mac and a working macOS with the Arq software installed.