i think it will also depend on the financial situation of a person. i do not speak for myself by the way.it is logical that if you are in a financial bad situation, its tempting to keep funds that you accidentally receive, because it is not a bank transfer but crypto, which gives much more anonymity. the sender should be more careful it think. but that is an ethical discussion.
It's more ethical discussion than anything else, and I agree with you, will someone return money or not will depend on financial situation of that person. Who has financial problems will take that money and cash it out quickly, who is has no financial worries will do the right thing. And we can't blame anyone here, sender who made a mistake should learn from that and if he is lucky maybe someone will return money to him, but if that doesn't happen he shouldn't blame anyone for his own mistake.