The biggest problem is lack of trust in crypto by people who are not in it. This creates ignorant panic (eg bitcoin is a bubble and will be worth nothing) and it also results in governments and big companies like banks and credit cards from facilitating crypto transactions.

I think the lack of trust stems from:
1 not understanding the importance of the technology
2 lack of regulation and kyc
3 all the scams and hacks over the last x number of years