If mech arena is not pay to win
Then it wouldn't be p2p benefiting most from SP dropping. Every knows how nomad is the most successful SP dropping mech. Nomad is a p2p mech. SP dropping exacerbates the problems in the gam. That includes certain items giving a significant advantage. In this case a p2p item.
I wouldn't say it's impossible or even super hard for f2p to beat p2p with skill. But p2p still has a significant advantage. Though I know mechs like Nomad will become f2p for now they are examples of p2w items.