The previous statement needs a bit of qualification.
If all you are using your Mac for is basic home use such as web surfing, emails, and streaming, then the previous statement is very valid.
However, if you are using for business or work on projects were you can spend a lot of time working on something and the apps do not have any autosave features (most don't), a UPS will at a minimum give you enough time to save all that precious work in the event of a power outage or even a survive a short power dropout. When I had a home business, I only needed this to happen once before I learned a hard lesson and bought a UPS. Also, depending on the capabilities of the UPS, you can sometimes work through a short power outage which is especially important if you have any deadlines.
So my conclusion, if you use you Mac for basic "casual" use, you don't need a UPS. If you use it for business and important projects, it is something I would strongly consider.
Robyee wrote:
Does the Mac Mini M1 have an internal 'battery' or capacitor
or in any case a system that protects it and doesn't make it shut down immediately in the event of a power cut or surge?
...
If the power dropout is a second or less, the Mac will likely not shut down but any peripherals may. Any power outage longer than a second, it will shut down. That "one second" margin is built in and generally required by the EU regulatory requirements for line operated computing devices.