Wanting to use an RFID reader to arm/disarm

Bit confused by all the options and how smart/complicated the hardware needs to be

there’s this on eBay that looks a bit mysterious.
Or is it something I should just run on an ESP32 or a Raspberry Pi? I’ve seen all sorts of networked, MQTT and standalone projects - is that simply because there’s a lot of ways to skin this cat?

There are many ways to skin the cat, and RFID is not really secure.

Don’t get me wrong, many people use them. But someone with access to your fob or card can clone it easily and quickly.