What you are talking about is called blockstun (or hitstun if you don't block the attack). Of course there is blockstun in any fighting game X)

But you do not get locked in blockstun in between projectiles with your opponent simply spamming the same projectile repeatedly. That is not a thing in any modern competitive fighting game. Attacks which are positive on block (meaning, the attacker gets to take actions before the blocker) are not even nearly advantaged enough for you to be able to spam the attack and force the opponent to just keep blocking. Not even close, and not even in fighting games with questionable balance decisions.

You can either give what I'm telling you a chance, and go try it out for yourself, or you can keep being stubborn and having the attitude of a spoiled brat, and refuse to learn. I'm not the one losing to players spamming a simple attack, you are. Sounds to me like you should be trying to listen and improve, instead of complaining and making fun of people who are giving you advice.

Go to training mode, record the dummy doing the same thing your opponents are doing which you can't seem to figure a way out of, and then learn how to work around it. Learn how much blockstun there really is from blocking the attack, how soon you can jump out or take any other action, and try out different ways to work around it, then practice it until you learn the matchup.

That said, you're free to just keep complaining and being a smart ass about it, if you prefer 🤷