The issue is finding what is a level playing field for PP when everyone chooses what field to play on.Mode choice, like ship choice, loadout choice, engineering choice, activity choice, is but one of many choices that may affect a player's game experience or their ability to affect the game.
First define fair when referring to affecting game features affected by PvE actions in a game where other players, and therefore PvP, are an optional extra.
To use the analogy of football: solo is individuals kicking balls into nets on separate pitches, PG is inviting your friends onto your pitch and x4 the score, Open is having you kick balls during a pitch invasion where people do what they like.