Most commercial transactions in modern societies are based on an explicit or implicit protection of both parties (seller - consumer). The protection may be provided by an intermediary party or ultimately by the law.

When I buy a product or service online with my VISA, I can reverse the transaction if the seller does not deliver according to terms.
For larger purchases (car, home) the transfer of funds is usually through a bank (which can authorise a cheque or provide proof of deposit of the amount).
In case of dispute I can ultimately seek protection from law.

I know that these systems of protection sometimes fail, but this is not the point. Even the implicit sense of protection often facilitates everyday transactions.

On the other hand, transactions with cryptos are based on trust, at least as long as cryptos are not recognised as legal form of payment and remain anonymous.

Do you agree that this lack of protection is an obstacle to the wide-spread use of cryptos as money?
What solutions do you see?

Bitcoin's base layer transactions on the blockchain are irreversible and final. It's no exaggeration to say that the entirety of bitcoin's system of blockchain, mining, proof of work, difficulty etc, exist to produce this history of transactions that is computationally impractical to modify.

In the literature on electronic cash, this property was often refer to as "solving the double-spending problem".