What is the difference node-red-contrib-zigbee and zigbee2mqtt

[wimdirks]

I still don't understand the difference. I am using node-red-contrib-zigbee and a CC2531.
At this moment I have a node red flow to control a zigbee light, simple switch on and off.
There is a node-red dashboard button that send a command to the mqtt broker via a mqtt out node.
When I receive the command back via the mqtt in node a zigbee herdsman node sends the command to the light.
This works as it should (I think).
Now the big question:
Why should I use zigbee2mqtt? What are the advantages?
Wim Dirks
p.s. Trying to dimm the light brought me here.

[wimdirks]

Anyone, please?
Or is this a very stupid question?
Stiill, I would like to dimm the light using node-red.
Any help?