There is no requirement to use the tradfi ramps. It is merely offered as an option. But as it pertains to banking in the USA, a couple differentiating qualities I will offer before the goalposts will inevitably be shifted yet again to damn my response

1) Settlement time (wires only sporadically free in US, plus usually settle slower)

2) Irreversibility.

3) The tradfi ramps, if used, only have to be OK with crypto ramp, rather than the whole host of underlying transactions. It is conceivable some banks will tolerate crypto while not tolerating, say, directly handling a particular transaction.

4) Lowered friction for international transaction

5) One or both sides can be unbanked.