Credit card points. I know it's looked down upon here but if you don't use them in the US everyone is getting a 2% discount on life at your expense. Unfortunately the poor are victimized.

I use citi cards (double cash and costco visa) then pay off using Fold card via Paypal for extra 0.5% in sats back (used to be 1% and higher but sadly was nuked) for ~2.5%-3.5% spend back.