If I had to offer you advice (not that Iām the best Lucario player around, but yeah), Iād say you definitely need more offense. Far too often youāre standing still, waiting for them to attack. I watched maybe three or four of Sonicās videos, and vs. both Sonic and Olimar there are points where you are content to sit back and wait a while before doing something. If you are sitting back, you need to be doing something. Try throwing out (or even spamming) more un-charged fireballs when youāre sitting back in defense mode. Unless youāre playing against a character than can spam fireballs back at you, theyāll probably be forced to jump over them towards you, or sit there and block the things. Thatāll open up your air game, as you do have a lot of priority to get right in there and attack.
Basically, your Lucario isnāt pressing the issue enough. You can go toe-to-toe with pretty much everyone, and you shouldnāt be afraid to get in there and get hit. Lucarioās attacks chain so well, if you get into an in close situation where youāre trading blows, you have two fast moves in Dair and Nair that can more than likely bail you out. In fact, you should be just fine with getting hit (not that you should try to or anything), as it ultimately raises your KO power, and makes your fireballs that much better.
Donāt be afraid to chase! Often, you get a Fair sending them off the edge, and then you back off and wait for another option. You have to follow that up! Use your second jump, throw out a Fair/Nair/Dair, anything. If you do have a charged fireball, jump up and throw it at them. Oftentimes this can alter their recovery if thereās a big aura sphere in their path, helping you get more chasing opportunities. I did notice that when you were completely on the offensive, you had way more success than when you were sitting back waiting for their move.
Just put more offense out there, and you should be fine. Iād totally be willing to play you sometime, if youād like. I need to improve my own Lucario as wellā¦
EDIT: Just as a side note, it also does depend on who youāre playing against, as going all-out against some opponents that zone really well can get you killed fast (ie Lucas). In those situations, you have to really watch your spacing and take advantage of opportunities when you get them by connecting with combos.