So here’s my question to you, guys: why do you think so many players, even the ones who really try, still don’t end up making money? Is it just bad luck, mental leaks, or the fact that they aren’t ready to put in as much work as this game demands?
No, no, and no. It's not bad luck, it's not mental leaks, and no, it's not a lack of work, either.
Poker is easy compared to most games; you don't actually need to put in that much work. Especially if you've already spent a lot of time on it, I can guarantee you that "more work" is not the answer.
And tilt is also not the answer. If it were tilt, then unless you're tiling all the time, you'd have a solid winning record most of the time, with a few major dips. You didn't show any stats, but I think you would know it if this were the case. The fact that you have to guess what the problem is shows that it's not tilt.
The problem is almost certainly that you're ineffective at improving. This also follows from how you talk about in the OP (and not just you, it's how most people talk about it). You're treating it as a social contract. "I did X, Y, and Z, I put in N many hours, now I'm entitled to be good". It doesn't work this way. You're not getting better by putting in work of fulfilling social obligations; you only get better by actually getting better. This is different in most other games, where you can just kind play and maybe study in a suboptimal way, and you'll still improve. Poker is different (mainly due to the lack of feedback while playing); it's uniquely easy in this game to play or even "study" while not actually imrpoving.
For example, suppose you're watching a strategy video. It's probably not part of a tutorial or carefully crafted series, but just whatever latest video popped up on whatever YouTube channel you're following. Maybe the video is titled "3 MISTAKES people make with pocket Jacks that COST YOU MONEY". You spend 20 minutes watching the video. Afterwards, you're playing for 2 hours. You're getting pocket JJs for the first time after 30 minutes. Now you either don't remember to think about the video, or you do but it's not applicable in this case (because it was probably a bunch of GTO charts you can't remember anyway). You probably implement none of it. By the time you get your next JJ this session, you're not even thinking about it. Then the session is over. By the next day, you've forgotten it completely. Now you've spend 20 minutes "studying" but how much improvement did you get form it? The answer is 0. If you multiply this by 1000, you've now spent a lot of time studying, but the improvement you got is still 0. I think this is probably what a lot of people do.
If you are serious about getting better, stop watching random videos. Stop watching any pro games if you do. Stop watching random hand reviews from other people. Search up a specific resource that you think is good that covers a few concepts, and then focus on implementing those particular concepts
for an extended amount of time. Don't look at something else every day and then think about it twice during your session; have a small enough number of concepts in the "current improvement" bucket that you have the mental bandwidth to constnatly reflect on them during your games. Always ask yourself if you're actually applying the concept in your games, and if you're not, figure out why not and fix it.
And also, review your
hands. This is actually the best demonstration of my claim that almost no one is effective at actually getting better. We have a hand review sub-board where anyone can just post their own hands and get advise on what they did wrong, for free, without limit. Reviewing your own hands is absolutely crucial for improving because it shows you whether you implemented a concept right or not. It fixes the problem of feedback that makes poker uniquely hard to get better at. Yet, almost no one posts there. We have less than one new submission per day. And I know why; posting there is hard. You have to show everyone that you're making stupid mistakes. Then you have to let othters tell you what you did wrong. It's a little humiliating. It's certainly not fun. It's so much easier to hang out in the remaining forum and talk on a high level about topics where no one can verify anything. It doesn't help you get better, but it certainly feels nice.
If someone actually cared about improving their game rather than feeling good, the rational behavior would be to keep posting hands for review until others tell them that it's too much and they should stop. Yet, again, no one is doing that.
I could have written a much friendlier reply, like "oh you just have to believe in yourself, then eventually your results will improve" or "It's just a matter of discipline, if you just don't tilt during your game, then thing will be fine". But I think those things wouldn't be true; in the truth is what I wrote here.