You might ask yourself if the luxury brands you buy are actually as high quality as you think. Do you survey the items for signs of superior quality? It's not a very easy thing to do if your not educated in the matter.
I'm not suggesting you are wrong in your thoughts or beliefs, but you might discover that some products are not evidently higher quality and that the assumption of quality came about as a result of its association with the idea of of luxury and aspiration.
for example, clothing construction at the higher levels is not exactly easy to judge. I don't know anything about stitching patterns or common fail points, but if Ralph Lauren advertise in a way that suggests that the people who wear their clothes are also the people who wear Rolex and drive Mercedes, people will make that connection.
Even if you think immune to this stuff, you aren't. If you think you could be classified into any particular social group, you are probably riddled with these kind of beliefs. I think it takes a prolonged and deliberate effort to avoid the tricks of advertising
About clothes: Since my wife is sewing a lot for herself and our kids, and does this very well, I can see the quality difference towards normal clothes so much.
My tailored suits already opened my eyes before, but in common day items it is ever more apparent to me now. Seams that don't fit or are crooked, stitches missing etc.
With respect to BMW or Audi etc. Most of the 'quality' comes from constant re-iteration of reviewers calling something high-quality, just because it is the way they know it.
Clothes and accessories are more straightforwardly signaling devices. Cars are interesting because they split the quality vs. signaling divide. To some of my friends, the point of a good car is to be seen in it. To others, like my dad, the point of a good car is what you can do with it alone on a country road. If may only leave the garage when you're taking it out for fun; you roll up to work, social occasions, etc. in your more ordinary daily driver.
That perceived quality difference of aspirational brands is caused by a halo effect. Functional differentiation is severely limited and inferior to competing on a sense of shared purpose which lifts brands above the competition within product category. Nike, Tesla, Starbucks all do this.
High quality luxus items have a quality of their own which has nothing to do with aspirational aspects.