If you're facing a Falco that goes full screen and lasers, you can sit in your shine until he decides to engage you in SSBM and actually fight. You can also take to platforms and use them to traverse the level and get closer. Remember that any Falco dumb enough to run to an edge without a plan is essentially cornering himself (think boxer cornered in a ring). He's basically saying "here, take stage control, take center stage too, also you can have positional advantage, btw you can corner me and I can't escape".
If you're on FD the goal there isn't to win neutral or beat the laser game. You already lose neutral once your feet touch the ground on FD because you can't avoid lasers at all. The aim on FD specifically is to hit him once and kill him (chain-grabs, usmash techchases and proper edge-guards, no platforms for him to recover to, etc etc).
The basic mindset vs Falco's lasers (or any strat you can't outright punish consistently) should be:
- Can I punish this? No, it seems difficult / unsafe / inconsistent to get a clean punish every time
- Instead of punishing this with attacks, I will punish it with movement + positioning
- He is running himself into a corner, so I can take positional advantage and trap him so he can't run.
If you're close enough, he can't laser. You can SH nair him premptively and stuff him, which forces him to fight you straight up (and you will usually win with your superior dashdance game)
Good luck!