For SL I don’t think there’s a major difference (however it does vary a lot depending on the vehicles you use and your skill level). However in ASB the SL gains are atrocious. For RP air probably has double the overall RP games for similar performing matches than ground, AND that will air having nerfed RP gains due to RP being tied directly to match length.
I don’t see any need to change these rewards, because making them harder to get is blatantly an anti-player action for no reason.
If, for whatever reason, they wanted to use the multipliers (like x3 in SB), they should have put x3 for realistic too, it would have kept them very alike, but now it’s a major nerf.
Now, it does make a substantial difference, because it’s not “just 4k SL”, you have to apply the multiplier !
So, with 1 premium vehicle and 1 premium account, you’re already looking at ~12k loss per award!
Two average matches, the ground match was slightly better and got slightly more rewards out of it; but both are for the most part equally average matches.
Ground progresses faster than air for me, because I’m better at ground than air.
Air progressed faster than ground for me for a while because I was better at air than ground.
Being better in one mode will get you more rewards in that mode.
I am a top 5% player in ground and a top 3% player in air. The only reason I tell you this is because I have never not had SL issues from day 1. You not having issues likely stems from you not having the exact same way of playing the game as everyone else and your particular way of playing saves SL. See: Playing one vehicle ad nauseam.
I ground all the way to top tier before going back to vehicles i found i liked. so i pretty much beelined straight to the top over about a year of playing on and off. Only when i started experting crews did i start to run short on SL. and now its only the gambling crates that bankrupt me.