Shield pressure is meant to cover options, yes, but so few characters can shield pressure so absolutely, and the ones who can, should do so while mixing in grab attempts. If while shielding you hold the C-Stick left or right, it'll buffer rolling at the soonest possible opportunity. If you're paying attention to your opponents habits when shield pressuring, you can use a move OoS to swat them away. If you notice their shield pressure puts them in front of you and isn't perfect (as most characters aren't) you can grab them in between moves.
There's a reason the meta has more of a focus on all the intricacies of grabbing and tech chasing rather than shield pressure, and it's because very very few characters have the tools to shield pressure so well that the opponent can't find a way out. But grabbing is instant, leads to combos or tech chasing, and when used right is a better mixup. Grab game is just more important man. Soz.
And Falcon can run after the opponent and grab to chase rolls, use movement around the opponent to bait out attacks and then punish their ending lag, jab their shield and then grab the opponent, and land behind them when they're shielding so they can't retaliate well.