Merchants don't adopt Bitcoin because their clients don't use it. Clients don't adopt it because merchants don't support it, and people want to have a payment method that can be used anywhere they go. How can this vicious circle be broken? Who will make the first move?
And by adopt I mean adopt for payments, not hodl it as an investment.
that's why there must be a liaison, in this case a third party to bridge this. let's take the example of what the el salvador government has done some time ago. they act as intermediaries between merchants and users. make regulations and then slowly adoption can be done.