I know some of this has been said already, but here's my take on it since
@Tanya-Fan-28 and I have played quite a bit. My "unnamed" old trainer that has won a few tourneys in his time broke down how to make reads like this:
Your opponent's
- intelligence (moderating use of unsafe moves/strings, playing solid neutral, being patient, taking and stealing turns at every opportunity, reaction time)
- creativity (using moves/strings for different utilities instead of just to open people up, mixups and lack of pattern)
- execution (confirms, rarely if ever drop combos, punishing most/all including whiffs, anti-airs)
The higher level player, the sharper all three of these will be which can sometimes make it very difficult to make the correct reads consistently. As someone that staggers a LOT with a 9f mid, my advice would be to do everything in your power to not let yourself be conditioned. If you allow this to happen then you're giving them false power over you by allowing them to create the fear of whatever they can do, when instead you should be focusing on how you can retake your turn.
The other part of that is knowing what's safe/unsafe and when to take your turn back if you're going to go for it. For example, recognizing the timing between someone inputting the first part of a string that's actually negative or habitually doing the part of the string that's plus on block. Sometimes there might not even be an actual pattern and you just have to be able to react to these small windows as soon as you realize they aren't continuing a string/cancelling, etc. Another key to that is being able to flicker block while ducking (which I've seen you do Kitanya) so if by chance you don't retake your turn quick enough, they whiff a throw and you have all day to full combo or D2 KB into whatever you want.
It's all about balance because if you're impatient then it's more likely you'll get blown up, but if you linger too long then you end up turtling and take more chip or even the throw. It also helps to know more about the frame data for those MU's you find tougher, especially if you keep getting mixed into a plus frame rush that you're having trouble countering. And with that you can't let yourself overthink, that will just hinder good reaction time. Eventually, instinct can lace with reaction time and especially during longer sets will be a noticeable improvement if you work hard enough at it. Just d1, mashing, or whatever you do also sends signals to the opponent as well. Make sure you send the right ones of "back off" if it's preventing their most rewarding option. You can successfully condition the opponent from even attempting that kind of rushdown or mix as much if the reward has been proving minuscule to them at times.
There's not a certain science to all of this, and like others are saying there is definitely some luck and chance involved. These are just certain measures that you can take and can provide more of an advantage with your game plan. Sometimes you'll "guess wrong" but it doesn't mean anyone should panic and mash every time they do it either.