being f2p only means u have less resources to work with, but at the same time u opted to work with what u have in your hands, not that theorycrafting bout "metas"

it all depends on what ppl (like, player) wants from game, and his/her logical sense. if u trying to be BEST OF DA BEST - logic declares that u need to whale. if u just want to run the game and enjoy it - u can be casual.
but ofc, if u want to have a spot in top 100, u either need to be whale, or very dedicated f2p/dolphin