“They mostly just gamma scalp” That’s literally all you need to know to understand the validity of the guys knowledge. Gamma scalping is one of a dozen trade techniques that can be more or less effective that other strategies in a dozen trade scenarios. There are many firms that do what his firm does. There are firms that front load tons of short theta. There are firms that arb tail hedges. A good options trader does all of it on a day to day basis.

Even if you’re chasing vol tickers, the tax implications and carry rates will be of greater trouble than value

I don’t need to have been trading for years to know this. All I need to know is how options function and understanding the right questions to ask when the opportunities present themself