What does a ticket lawyer actually do?

So I got my first ever ticket for speeding. I hired a ticket lawyer as everyone told me you pay him and it gets dismissed or he works out a deal, in the long run it may work out the same value as the ticket but the added benefit of removing it from your record.

Anyway, I ended up getting deferred disposition, and paying $300 court fees (the cost of the ticket).

From what I read online I could have just requested deferred disposition from the judge myself? So I basically just paid a lawyer for no reason.

Am I missing something here? Feeling pretty bummed when I believe I could have just requested this myself rather than paying an attorney.