Kinda agree Alphonsus, but to be fair to the broking profession...

Kinda agree Alphonsus, but to be fair to the broking profession there's a bit more to it and some premium service if you need it.
The Firms usually have access to more early stage funding opportunities for sophisticated investors and also restricted offerings that you may not get into through online comsec, etc. Pre-IPO and seed.
For large sell/buy orders they will also manage the implementation of those orders a bit better (in theory at least).
For off-market and x-trades they will manage that process also and maybe find that buyer/seller through their channels when you don't want to upset the market on-screen.
You are right to say that an individual with a bit of nous can handle most things but there's a reason that larger sums of money and more complex portfolios need management assistance and that's what those guys do and more if you have the coin.
The better ones know how to throw a pretty good tactical info/network event with interesting speakers and a full bar.
Generally a fairly entertaining bunch if you know how to swim with sharks.

Hardrock