I’m just telling you that no normal (and by normal, I don’t necessarily mean good!) leader (i.e. one who is not a megalomaniac, a narcissist or a (wannabe) dictator) would demand a military parade for their birthday. Honestly not. And even if you don’t care because it’s “symbolic,” you should still care because it shows you the type of person he is.
So if you already have a negative opinion of his character, it reads as demonstrating a negative aspect of his character.
Don't get me wrong, you're right about his motivations, but it's still based on personal interpretation. He's not explicitly saying it's about himself. And it's a reasonable interpretation, but if someone doesn't see him that way already, this won't convince them. This sort of plausible deniability is part of Trump's MO, he wants to be criticized over such non-substantive issues, because it makes it look like it's the most severe criticism people have of him, and it allows him to control the narrative and draw attention to the parade, which the average person will probably not have a problem with, because people like parades.
Instead of taking the bait and freaking over every random, forgettable news cycle, it's better to keep criticism focused on things that have a material impact on people's lives, such as tariffs and deportations. Deportations in particular are much more of an indication of fascism than a parade is - people are being abducted off the streets and taken to black sites with no due process or oversight. If Trump wasn't doing shit like that that actually affects people's lives, he could dance around however he likes and I wouldn't mind.
Maybe I'm just a spoilsport, but my hatred for Trump is disciplined. I don't see any reason to freak out every time he sneezes. I'd rather focus on the important, unambiguously bad things that he's doing.