As the old saying goes, you get what you pay for. Having said that, you often pay a lot more for that extra 5% or 10% gain. The question is whether it is worth it. For me, if you can afford it, get the better or best. But if budget is a concern, there is nothing wrong with the RP. I have one and I feel that it does just fine for everything, even for action and BIF shooting if you know how to manage it.
The R5/R6 has animal eye-tracking which the RP does not. So if BIF shooting is important to you, the R5/R6 will excel here otherwise, the RP auto-focus is really good (much better compared to my 7D Mark II that I used to use to BIF).
