Well, as I explained,
savings is a demand for Bitcoin that isn't the same thing as "hopes and dreams of getting rich someday". Just having an asset that doesn't reliably evaporate like the peso or the bolivar is a pretty big win already, even if you aren't going to get rich.
Another important use case that I didn't mention is leaving the country to live somewhere better. Suppose you've saved up money in, to use examples I know something about, Argentina or Venezuela, and you've managed to do it in a form that doesn't evaporate due to inflation: US$100 bills, emeralds, gold, real estate. Now you want to move to Spain, Uruguay, or Mexico. Getting those savings safely out of the country with you is going to be very challenging indeed; Argentine customs has dogs that are trained to sniff out dollar bills, for example. (And of course in the case of real estate it's impossible.)
Again, maybe this is an example of "buying illegal shit": you aren't supposed to be able to escape these places with your life savings, because otherwise how can kleptocracy keep klepting? But obviously (at least to me) being able to take your savings with you makes the world a better place, even if it's illegal.
But it's definitely not "stripping wealth from the global poor and draining it back to the wealthy ones". The "heavily regulated", "government insured", "government managed" world banking system is what does that.
Maybe fleeing the country like this sounds like an extremely marginal, unimportant use case to you, but if so, that's probably because you don't know anybody from Cuba, Ecuador, or Venezuela. Not only are significant percentages of those countries' populations already living abroad, but even larger percentages of the people living there today depend on family members living abroad.
I don't know anything about Bangladesh. I've never been there and I don't know anyone from there very well. Maybe the situation is different there and Bangladeshi people only invest in Bitcoin because they think they'll get rich. What are your experiences there?