And how do you expect to force him into the air? You're jigglypuff not snake. Your ground game may as well not even exist. So not only do all his aerials outprioritize yours aside from pound (which gets extremely punishable and predictable), but his ground game outprioritizes your air game as well (F Tilt, SL OoS). Play a good mk and you'll realize how limited your options are.
You don't need a good ground game because you have useful grabs. Pound is also a useful tool in vertical launch, and on top of that it's pretty high priority and easy to land. (And punish if you don't use it right) This isn't exactly an easy task, but because you do have some options, this is 5% of the matchup in his favor.
In the air it might as well be a 50, 50, but he does out range you a bit with faster (but weaker) aireals. If this is the case, he has another 5% in his favor. 40:60 is the lowest this matchup goes because in the air you can outspace him (not with ease) and out power him with your f-air as a kill move, and drill rest. (which is still one of the most reliable ways to land rest.) By the way, rest kills him around 65% to 70%, and that is just about a safe amount to get from him while you fight him in the air.