It depends on what we understand by "anyone can make it". I would argue that, if understood in terms of "anyone can [become orders of magnitude richer just by picking the right investments]" then that indeed is a narrative that is harmful and should be contradicted. Yes, of course outliers happen, and anyone may become stupidly rich from a low income if they're lucky. That doesn't mean it's a good idea to try, and people on an individual level should be discouraged from taking such huge risks unless they are very consciously aware of the consequences of their likely failure.
The other side of the issue is a systemic one. If a society finds it traumatic to accept that there is a likely upper limit as to what people can hope for based on their wealth and opportunities at birth, there is deeper problem. The problem may be cultural in that a society's members are too instilled with self-centred and unrealistic expectations (i.e. a culture of temporarily embarrassed millionaires), or it may be a deeper economic issue regarding inequality of incomes that makes surviving at certain levels of income without any hope of the smallest improvement leads to greater desperation and dreams of "breaking big". It may be a mix of both.
Coming back to "anyone can make it", it should be defended, but in the sense of "anyone can [reach a level of economic security to live a fulfilling life]". That however is not a principle to encourage the individual through dire straits. Rather, it is a principle that should guide public policy and cultural attitudes as a whole, so as not to have a society like I described earlier. In such a society the population won't feel the need take unrealistic risks only for a chance to get out of a rut or satisfy cultural fantasies. That's not to say it won't happen, anyone can be an outlier.
Maybe the part of society that contains the crypto enthusiasts. Every part of society with a shred of financial experience has been pointing out that 20% is really really high compared to the risk free interest rate. Of course, pointing out that something is unsafe will not make you popular with the people dreaming of getting rich.
Are you saying that the poor are just destined to remain poor?
I'm not saying the narrative they're told is correct, I'm saying the wealth disparities in society are undesirable and if just telling poor people to pull themselves out of poverty is not viable, we need other solutions to address those disparities.
Like you I think large wealth disparities in society are undesirable, but if those come from the way society is set up then society is what is going to have to change. If you really want to change society then set up a movement and convince large groups of people about your viewpoint, but be prepared for hostility from anyone with a vested interest in the status quo.
So what you're saying is people shouldn't expect to be able to massively multiply their wealth, but that directly contradicts the narrative that "anyone can make it" instead of the wealth and opportunities you're born into determining the likely upper limit of what you can hope for.
I'm not disagreeing, but it's absurd to condemn people for falling for "get rich quick" schemes (and as far as those go 20% is unusually low) when the entire society is built around maintaining the lie that getting rich quick is possible as long as you "work smart" (i.e. don't rely on your own physical labor to make money).