First off, how can you claim RCS "requires you to buy an Android and then state iMessage is "cross platform through Apple’s ecosystem? RCS works on Android and is available in various devices from many manufacturers. iMessage is only available on devices sold by Apple.
Secondly, why would you rate iMessage higher than RCS for “ease of use”? That makes zero sense, they behave basically the exact same way.
Lastly, RCS is coming to iOS - Apple’s just been lagging because implementing a cross-platform solution is detrimental to their profits.
So RCS will eventually work across iOS and Android AND work by default. There’s no reason RCS wouldn’t be easier or rated higher than iMessage in terms of “ease of use”