https://sonoff.tech/products/

https://alexmeub.com/automating-capacitive-buttons-with-switchbot/

Yes… but you can’t compare the range of possibilities that HA has, the USB version will be of little use to you until you run your automation system.

However, the bridge, regardless of whether the pro version, connects devices into one network and you have access to them via the ewelink app. Scenes and LAN mode are available locally, which provides minimal automation possibilities even without constant access to the Internet/cloud. Which gives you the ability to use your devices to some extent without having to have an additional PC with HA.

However, if you want to build your own HA based on a PC/SBC, you will need a Zigbee 3.0 USB Dongle. Think of it as adding a wifi card to an old pc that didn’t have wifi.

Which solution suits you better is your decision. If the bridge, you will be able to use the devices from day one. If you have a USB dongle, you won’t have a working solution until you run HA.

https://www.youtube.com/watch?v=SlgC7xhhzzE

An old/cheap tablet/smartphone as a display and one of these sensors…

https://sonoff.tech/product/gateway-and-sensors/snzb-02p/

https://sonoff.tech/product/gateway-and-sensors/snzb-02/

Or if you have $$$, NSPanel as a display… https://sonoff.tech/product/central-control-panel/nspanel-pro/

Are you planning/do you have your own automation system? For example, Home Assistant…

The USB version is a universal gateway for Zigbee 3.0 that adds this functionality to your device, for example you have Home Assistant, openHAB, Zigbee2MQTT and others… you add the ability to support Zigbee 3.0 to your PC and use it as a universal central hub/bridge without the need to purchase other hub/bridges.

If you don’t plan any of the above, start with SONOFF Zigbee Bridge.