So you dress in worse clothes to go to Church than you do for work because if you dressed respectfully for Church, you would be oppressed and it would suddenly turn Mass from a joyful occasion into yet another awful chore?
I can imagine some people would genuinely believe something like that, but that comes off VERY strongly as just an excuse to dress in regular clothes to church rather than a reason. Some people don’t like to wear nice cothes, but there are plenty of times where they are necessary. You don’t necessarily need to wear a full suit and tie to church, but dressing casually in front of God when you’d never dream of doing it at work or in front of an important person such as a president speaks a lot about the level of respect and importance someone places on being in the presence of God. God is really present at the Mass. If dressing in shorts and a T-shirt and taking it easy in front of the president if you met him on a weekend because, hey, I’m not at work would be considered disresepctful and would have some consequences, I don’t know why you’d think it would be okay to act that way towards God. It’s not about “oppression.” It’s not about wanting to chill and be comfortable at Mass because it’s not a workday. It’s not about keeping up with the Jonses. It’s about reverence and respect. The purpose of the Mass is for you to worship God, not for God to give you a break from work. Saying “I don’t want to dress nice in front of God because *I *don’t feel like it and it makes me angry to be told I should” takes the focus off God and onto you. To put it bluntly, it doesn’t matter what makes you feel comfortable at Mass. The purpose it to please God, not you.
It’s also about Christian witness. If I walk into a church and everyone is dressed in everyday clothes, it would give the impression that this church does not consider the Mass anything special, and that assumption would almost certainly be right. A big criticism of Catholocism from protestants is that it seems like their followers just go through the motions and don’t treat church and God with the reverence they should. Treating Mass the same way you would a bar at happy hour after work (i.e, a place whose primary purpose is to make you feel good and relaxed and where you can take off your suit jacket and let go of your cares and worries after a long day at the office) doesn’t do justice to God and the purpose of the Mass.