Ill analyze gambling vs poker vs trading in three different dimensions
-1: House edge and winning odds-
A. Gambling: The house has a fixed edge of 10% or so, there is no skill, and you will always lose in the long run
B. Poker: The house still has an edge of 10% via the rake, but you are playing other players so if you are 10% better than other players (or 20% depending on the maths here), then you will win in the long run. Its very hard to get this kind of skill but its possible.
C. Trading: The house has a rake of 0.4% via commissions, and the game is based on skill. So its much easier to beat the game than poker if you are only 0.4% better than the other players.
-2: Risk-
A. Gambling: Typically betting 100% of your money which can be instantly lost
B. Poker: Typically bettering 100% of your money which can be instantly lost
C: Trading: Uness you are using margin, the loss is rarely 100%. A typical crypto loss is around 5-10%. On the worst of days, bitcoin goes down maybe 50% before having a hard rebound and if you have patience you wont even need to take that loss. You control your risk. You can set stop losses, you can catch rebounds. A good trader only takes losses of less than 1-5%, and makes wins of 50%+. Youd have to be in dozens of these losing trades in a row to lose your money.
-3: Bitcoin X factor -
Bitcoin has historically been in a bull market. Even with the 'rake' and even as a bad trader, the odds are always highly in favor of investors. Its still a zero sum game but the people who pay are going to be the big time investors that buy at the very top of $1M (or maybe it was $20K). So if all you do is make long trades, it is very hard to lose fiat (but easy to lose coins). This of course will no longer be the case once bitcoin finally fails.
Well, it seems that I could agree on your third "dimension", that Bitcoin has been in a bull market for the last few years, but for the "has been" part. You likely know it better than most posters here how bad this can play out in the end, which you seem to admit yourself. Basically, we can't read the future, and it is particularly true in respect to long-term investments, especially in the crypto world. In short-term or day trading this is irrelevant since you are mostly riding the volatility thing anyway, and it is not going to disappear any time soon.
The other two points are cherry picking. I had been gambling a little in the past and I'm somewhat familiar with the things there. Most casinos have a house edge of around 0.5-1% nowadays, so it is not much different from trading fees. And you don't typically stake everything.