It's the other way around, as far as I know: Unlike Google, Apple does not offer any RCS infrastructure. It's supposed to be provided by the carrier anyway, but not all do.
That said, I think there might be a secondary problem of carriers having to get their RCS configuration deployed via Apple's "carrier profile" system, which seems like a bit of a nightmare, especially for networks that don't have a business relationship with Apple.
But it's definitely possible even for MVNOs: US Mobile has been supporting RCS on their Verizon plans for a few months now, but not yet on T-Mobile. Not sure whether T-Mobile's MVNO platform or Apple is the blocker here.
Yes Apple has no RCS infrastructure, they do have a carrier profile system as you mentioned that means iOS devices won't support RCS on any given network until you get Apple to distribute the configuration for that network.
That said, I think there might be a secondary problem of carriers having to get their RCS configuration deployed via Apple's "carrier profile" system, which seems like a bit of a nightmare, especially for networks that don't have a business relationship with Apple.
But it's definitely possible even for MVNOs: US Mobile has been supporting RCS on their Verizon plans for a few months now, but not yet on T-Mobile. Not sure whether T-Mobile's MVNO platform or Apple is the blocker here.