What makes using OBD2 system, so much better than OBD1

I had OBD1 on my 89 Shelby Dakota. There was a service eng light or something like that in the dash on. Took it to the dealer and they told me after 125K there was no way to reset the lamp. He showed me where to pull the correct wire out of the underhood connector, and Poof! No more light. OBD1 was just a bandaid in the evolution.

That was horse crap.