Rich? It's extremely hard to be "rich" just by playing poker, but it's simple enough to make a living off it. The reason being that you have to be vastly superior to the field to make steady money off poker with a rake (like at Casinos). For example, in order for you to "break even" with a 7% rake, you need to be a 53.5% winning player. If you eat fancy casino food or take an uber home, your winrate goes even higher. In the end, you need to be around a 58-60% winner (against the field) to make money. At high levels, that winrate is difficult. It's only possible against a field of fish / tourists (lowest level, so $1/$2 or maybe $2/$5).
I was a cash game grinder. In fact, before my current job (that made enough money to make poker money no longer that attractive), I lived off poker for about 1 year. I was making around 1.5k a month doing 2 days a week (so probably 8 days).
My style is mostly pure math/logic due to the fact that I am casino player and most of other players (non-regs) are total fish. I only play at $1/$2 and usually each session is 5-6pm to next morning 5-6am (12 hours). I would do this Friday / Saturday. I average about 8 bb (big blinds) per hour overall (I performed much better in the last 6 months than the first 6 months). Keep in mind that live game deal cards much slower than online, so we are talking about maybe 30 hands per hours (so 8 bb per hour is doing quite well). I make about $200 a night and I am one of the better earners at the $1/$2 so I doubt you can make much more unless you play everyday (non-weekends are harder due to lower fish percentage and less action) or even you have a good bankroll to go higher ($2/$5).
Near the end of the year, I slowly saved up enough and I wanted to go to $2/$5. The competition was much harder at the level. First of all, there was one table instead of like 12 at $1/$2, so you play with all the other regs/sharks often. At the 1/2, usually you get 2-3 regs and the rest are either casuals or tourists. This makes all the difference in poker earning. I would say 90% of my poker income came from fish, there's literally no point playing against a decent player cause your winrate is shit (with the 7% rake, you basically need a 60/40 advantage again the player to make it remotely profitable). So imagine if you are sitting at $2/$5 with 6 other good/decent grinders facing like 3 tourist fish, that's way less opportunities than sitting at $1/$2 facing basically twice the amount of free money. So after playing about 2 weeks of $2/$5 and breaking even, I decided that my poker dream isn't worth it... I need to pay rent and eat so I moved back to $1/$2. I suppose if you live somewhere with A LOT of tourist (like Vegas), maybe the $2/$5 or even $5/$10 "could be" profitable, but you would need such a big bankroll to even endure the variance, so it's not something you can hope to do quickly (it would take like 1-2 years of saving at a lower level to move up one level).
All in all, you can only get "rich" in poker if you play at high levels. At those levels, the variance is too high so you better already be rich or else you live on the edge the whole time (any bad string of cards will make you unable to eat for that week).
The moment I got a good job that paid more than poker, I stopped pokering. Sometimes I do play a bit for fun, but it's different now cause I can afford to lose. When you are doing poker professionally and feeding yourself on it, the stress is intense and it's just not worth it (unless you like the thrill, but I am not really into that. I literally only play because I am good at it, I kind of hate playing it professionally).