It's not enough $$$ to be a full time role, especially considering the costs of purchasing health insurance w/o a traditional W2 employer, but it's perfectly possible to buy in for the the table max (500) and leave with between between three hundred and a thousand dollars in profit in ~8 hours of play.
(Real life, not online. "Caro's Book of Poker Tells"[1] will aid you more than fancy math, though knowing the basics of what is a good hand, what a check raise is, that sort of thing will help -- the biggest thing to remember is to play less hands, and be aggressive when you do. Fold or raise -- no calls!)
It's hard, because the bad players tend to play what is termed "loose aggressive" -- so you have to play less hands, and often they get lucky with crap like catching a flush draw or three of a kind, and they only play 1/2 or 1/3.
For privacy reasons I cannot give my specific location, but I've had good experiences at the Golden Nugget's 1/2.
(Unfortunately there's not much of a wall from the casino and I'm sensitive to smoke, so I didn't last long before getting a migraine -- maybe they'l outfit themselves like a dutch hostel with one of those big air sucking machines oneday)
OP may be highly skilled and disciplined, but the implication here is probably a bit exaggerated.
Assuming he is talking about buying in a full $500 at a $3/5 table, that's 16 big blinds an hour (16bb/hr x 5usd/bb * 8hr = $640), which is a god-tier rate in the long run.
For mere mortals with less skill and patience, it's also possible to lose the same amount the next 8hr session, resulting in a net zero for two days of work. Or, to sit break even for 8hrs with crappy unplayable hands, because you do need to play less hands to win as he mentioned.
Variance can suck out any profit from cash games and can get you deeply stuck for months on end (see: any full time poker youtuber). Tournaments are even higher variance.
And if you switch to doing this full time, you become self-employed, which drastically increases the cost of taxes, healthcare, social security, etc. Medicare tax doubles. Social Security tax doubles. You must buy your own healthcare, which drastically increases in premiums (unless you have a spouse who can add you as a dependent on their W-2 sponsored plan).
This really goes for any self-prop business/freelancing. In exchange for freedom of being your own boss, you pay in stress, variance, and taxes.
To make this work, you'd probably have to make double that per 8 hour session. Which is insanely difficult to do as a poker pro and sustain as a "full time job".
It's not enough $$$ to be a full time role, especially considering the costs of purchasing health insurance w/o a traditional W2 employer, but it's perfectly possible to buy in for the the table max (500) and leave with between between three hundred and a thousand dollars in profit in ~8 hours of play.
(Real life, not online. "Caro's Book of Poker Tells"[1] will aid you more than fancy math, though knowing the basics of what is a good hand, what a check raise is, that sort of thing will help -- the biggest thing to remember is to play less hands, and be aggressive when you do. Fold or raise -- no calls!)
[1] https://archive.org/details/carosbookofpoker00caro