The problem was that you used Dair and some other moves when they weren't going to hit and also while your opponent wasn't approaching so they weren't pre-emptive options either- you can use this time to position yourself.
Spacing Dair tho is a subtle thing-
Most commonly people will space a retreating Dair or Nair on an opponent's shield to avoid being grabbed and can position you to punish, you can also retreat with Dair to out-prioritize an approach.
You look a lot better in that second link despite losing, still a lot of attacks on shield though.
Be wary of that walk away-pivot-Fsmash trick of yours as it gets predictable, only worry when it gets punished though, you're Gucci otherwise.
You get a lot of hits from punishing whiffs in this link, but only when the DDD gave them to you for free- you can earn these yourself if you look for them.
^
You seem to enjoy playing rush-down but remember that the whole point of applying pressure is to crack your opponent so let up every now and then to either reposition or punish an antsy action.
You let go of your lead quite easily as well, you don't need to camp to keep it, but avoid grabs at all costs and in general as Falco.
It seemed that when you had space between you DDD could only throw his gross frog spawn at you so he was glad that you closed the distance and gave him more options.
Also don't approach him or Kirby of they're camping edge, especially if they aren't in the lead. The only thing I can think to do in those situations is bait but meh.
Lastly I recommend cutting back on the laser to Fsmash, along with Fsmash in general- you like that move too much man, save it for risk-free situations like tech-chases.