For most people I know, the (general, normal life) primary motivations for wearing what they wear are functionality and style/fashion. Church is no different.
I spend most of my week working in an office where smart dress is mandated, to create the 'right impression'. When I go to Church at the weekend I don't go to create 'an impression', I go to be me. Therefore, I'll wear whatever I'm comfortable in - usually trainers, combats and t-shirt.
One of this things I've found most difficult about leading the choir, is that I no longer attend Sunday Mass to be me, but to fulfil a function. I feel a pressure to set an example, to do a good job, to meet other people's expectations so I am taken more seriously. So, I'm dressing up. It certainly helps other people.
Shouldn't we should be beyond this? Thomas Merton says the humble person doesn't get flustered by things like what other people wear, or hang or their walls - because it's an accidental. It's not really important.
There are many people who dress in a conventional Church fashion, who make all the right noises and gestures. But their clothes and words and gestures mean nothing because they are not authentic - those clothes and words and gestures are not true for that person, they don't believe it. Likewise, some people wear hoodies or hats, tight jeans, lowish tops etc and may not have all the right words and gestures. But what they do do is real for them. They are not faking it. And all the different permutations in between.
But we are all here together. I'm reminded of a song I know;
Come, just as you are to worship.
Come, just as you are before your God.