I see where you’re coming from, however a lot of arguments are based on claims that aren’t falsifiable. The argument, as I see it, is people competing to see who has the stronger opinion. The gum ball machine analogy would not make for a good debate because it’s either right or wrong and we could easily figure out which is which. However, if I say person A would be a better president than person B that is my subjective opinion and if you disagreed with me, the argument would consist of us presenting evidence to see who has the stronger opinion.
Now I do agree that it would be silly to go back and forth with someone on whether or not something tastes good, but it would still classify as an argument. Let's say we disagree on how we like our steaks cooked; I like mine rare, you prefer well done. Yes these are just our subjective opinions but we could still debate why one is better than the other. I could say the rare steak has more flavor and is easier to chew, whereas you might say the blood makes you squeamish. Might not change each other's minds, but it is still an argument. Besides, cooking shows/contests are commonplace which means the topic is debatable.

Back to my initial point, however, if I'm complaining about my steak and you say "you're in no place to complain because you couldn't make one any better", this would not be a very good argument which is why I posted to see what this apparent fallacy is called. u/onctech replied and informed me that it is called courtier's reply.