I went other.
I don't really 'grind', I am at the moment because there's two cars in the LCD I'd like to pick up (GT40 and CLK LM), but throwing in one of the big three races from time to time isn't really a chore as they're not bad combos. I don't even know how to AFK grind and haven't rubberbanded the controllers since GTS.
I'm also not a big critic of the economy, as I've said before I'll be playing GT7 until 8 drops, so I don't mind there being a long-term element to it.
In my humble opinion, the best all round option is to give every major track layout at least one ~30min ~500k race. Call it 50 layouts, that's 25,000,000 Cr without replaying a race or CRB, and it's a great opportunity to push players to use a wider variety of cars. Yes it would still take time to accrue a big pot of money, but it would be much more enjoyable.