It will depend on the person you are convincing with.
If you will try to convince an old person, they will find it overwhelming to the point that they will not be interested on it. On the other hand, if you will tell it to somewhat a Gen Z person or a person who's at the 20's or 30's, they might find it interesting for them and they might get curious to learn it as well.
I don't think it depends on the factor of how old someone is because I have seen members on the BTT forum, which are from octogenarian group (80 years) and some are in their 60s. The point is, that people are interested in crypto for profit, to make there future more secure money-wise. And according to you old ones might not like it, IMO that's because they are no more worried about there future due to numerous factors, (that's another talk) but there are old people who are interested in crypto as well, actually, age does not matter, the only thing that matter is, how much risk a person wants to take, how much interested that person is in adventure, how that person sees a technology, with what perspective.
This means, that old ones are interested in crypto because they praise its potential, and the knowledge it has given to the people, the trust that was among people for banks has been broken and that's what is called revolutionization.
For us who've been in the crypto for a long time, we know that it's real. The problem is those other people who doesn't even know that a thing called Bitcoin exists. Convincing isn't enough. Knowledge is needed for a person to know that it's a real, and it's existing.
I don't think after the ETFs approval we still have to make that much efforts to convince someone about the potential of BTC, yeah in case if the person is not even interested in making investment, and don't even know what ETFs are then its a waste to put your energy in convincing him/her.