All relationships — romantic or otherwise — are balance. In this case it’s balancing your individualism versus a respect for your partner’s opinion. That’s a highly personal decision, and I’d hesitate to offer someone else advice about how they should approach it.
Personally, I tend to be much more individualistic than deferring to someone else’s opinion. I would rather make my own choices than have others make them for me. I’m extremely picky about nearly every element of my life: what I wear, who I’m with, what I do with my time and attention, what I purchase, what I eat, where I go, etc.
I make purposeful decisions about those things. I’m nerdy and geeky about things, meaning I obsess over details a lot. I believe the choices you make should be meaningful and your own. This is why I hate to turn over decision making to others. I see no point in living a life that you’ve outsourced to someone else. You lose so much agency and control the more you allow that to happen.
But no one can live life completely alone, right? At some point you must compromise on a decision. However, I think the key is to realize that you’re not deferring a decision to someone else, but rather making the decision together. This means actually communicating toward an agreement and actually caring about that process and outcome.
So, it’s not just a matter of “should you let your significant other pick your clothing?” It’s a larger matter of if you’re OK with having your life dictated to you instead of dictating your life — and perhaps it’s not a bad thing to let parts of your life have a co-author.