People who are "budget conscious" don't buy FF, they buy a crop sensor system of some sort because it's more affordable. FF has never been "budget conscious".
When I had two E-M1 II's, I had two 64GB UHS-II cards in slot 1. When shooting at 10fps for 3, 4, or 5 seconds, I want to clear the buffer as fast as possible, because you don't have full function of the camera while it's writing to the card. It's even worse if you use the 60fps S-AF mode for taking a number of shots quickly (i.e. stacking/merging in post).
What's the point of buying a high speed camera if you don't take advantage of the speed? It's a bit like buying a Porsche, and then putting all-season tires on it. Sure, it'll work fine, but you're not getting the full performance out of the vehicle.