For complete system backup on Windows use Acronis [0], on MacOS use Carbon Copy Cloner [1] and on Linux Clonezilla [2].
Also never forget the 3-2-1 rule of backups [3], 3 copies, 2 local copies on different mediums and 1 copy offsite (cloud, remote) :-)
[0] https://www.acronis.com/en-us/personal/computer-backup/
[3] https://www.backblaze.com/blog/the-3-2-1-backup-strategy/
Going by the names and the descriptions I've read, the overloaded term 'backup' only applies to Carbon Copy Cloner and Clonezilla in the sense that they make a copy of your storage, so don't protect against corruption (such as ransomware, or you accidentally corrupting files, or deleting files...) Please let me know if I'm wrong on this. Of course you can do real backups with a clone-only tool if you rotate the backup media yourself, but I prefer this aspect to be handled automatically.
Carbonite backups up 24/7 so I have even the latest changes. The only painful thing would be to find a new/similar laptop to restore my data.
If it would be a different brand laptop, then I would have to go through the pain to setup most stuff. Chances are that restoring to a new laptop may work right off the bat, even if I will have to spend X hours finding appropriate drivers (better than setting up everything from scratch).
It has saved me a few times. In particular it saved my ass when my brand new OCZ SSD died on me on day 2. Due to being full-disk backups, I was back up and running in 30 minutes on a spare HDD with no essential data loss.
For Windows, a similar strategy is possible, but I consider my Windows box disposable (only gaming), so don't have much recent experience.
Unless your NAS is somewhere (not your home's internal wifi network but a WLAN). Consider a Carbonite (or similar) that has infinite backup space to make sure you have the 'offsite' covered.
Honestly though, low effort is very important for me. After all, any solution is simply reducing the odds, not completely eliminating them.