If you're having trouble with Fox/Falco, play better.
OOOOOOOHHHHHH!!!!!
I've described this before but I'll do it again, because it's hilarious and has stuck with me in a beneficial way.
My first stock (ever) against a ZSS, I was Zard.
She did a charged shot at 0% (first thing I ever SAW from a ZSS), I PS'd it and combo'd her out of a Stun > D-Smash. (good start for the lasers)
The final hit of that stock, was an UNcharged laser > Dash toward me.
At the same time, I Dashed up > PS'd the laser > Up-B'd OOS (she was gonna grab but it's too slow) and killed her off the side.
She probably hit me with a laser somewhere in that stock otherwise, but given how much it worked against her, lasers sucked in that stock.
It's been consistent like this since, every stock of every game, and when I play ZSS, there's almost never a blaster shot in the neutral game. I'm sticking with this approach to the character. lol
Blaster is too slow, not just the projectile, the start-up and linear application of it within that 'fire > dash' window (Edit: You can even just Dash toward her anytime she SH's (such a slow SH). If she Side-B's or aerials, you're safe with spacing and a WD out, if not, she's likely going Blaster and it's easy to react to, free hit for YOU, and your Grab will just go through her start-up/the shot itself anyway)
Just DD, wait for it, and approach her. It's easy to get more often than not, even at this point, let alone when the meta-game advances to some decent extent.
In other times, outside the neutral game, yeah it's good. Free grabs for DK if not.