I think several things can simultaneously be true.
There are lots of practical reasons to wear a bikini.
They make it possible to have a different size top and bottoms, aren’t wet and clingy when you’re on the beach, allow you to get a fuller tan, and are easier in the toilet.
So many women will choose a bikini for one/several of those reasons.
However, women who say they feel sexier in a bikini or the other clothes mentioned on this thread are absolutely being influenced by the male gaze. The whole point is that it’s a subconscious influence, you’re not deliberately choosing bikinis thinking “the blokes at the beach are going to love my arse in this.”
We are bombarded with images of what attractive women look like from childhood. Today it’s social media and celebrities, but before that it was magazines and the golden age of Hollywood. All of us have been subjected to the social conditioning that tells us what looks good. And it’s always about what men like. All of this messaging says you can’t look sexy unless you’re revealing lots of your body and squeezing into (usually) uncomfortable clothing.
You might think you’re just dressing for you, but the influence of the patriarchy is there. It’s short-sighted not to acknowledge that.
Having said that, I 100% support every woman in deciding to wear what they want. It doesn’t matter if the male gaze has influenced you subconsciously; if you enjoy wearing it then crack on.
I just think it’s important that we recognise preferences around what “looks good” almost inevitably have their root in male gaze, whether we realise it or not.