I am a former online poker player, I spent a long time watching videos, reading books, practising, collecting and analysing data etc I think I'd played ~500k hands by the time I stopped.
I was an overall winner, but not a great one and while I can (could) comfortably beat 50NL for a reasonable income over time the playing standard improved and I wanted to play higher stakes and got crushed every time I tried.
So now I play once in a while for some fun and leave it at that.
As far as luck goes, here's my take on it.
There are 2 extreme samplesizes. i) an infinite number of hands. ii) one single hand.
We know 100% for sure that given an infinite number of hands that you will be 'lucky' exactly as often as probability says you will.
We have no idea what is ever going to happen in any single hand.
Any samplesize that a player plays for is a subset of i) the closer this subset gets to being i) the closer to average the results get, but as you can't ever get there the results won't either.
Different players have different subsets, and some will run hotter and some will run colder than expectation.
People call this luck. Maybe your fated to only ever experience the colder side of the curve. Maybe it's all completely random and all of us suck at understanding random, what with having brains that have pattern finding fetishes.
If you played long enough it would all balance out, but you only get so many years and can only play so many hands.