Modesty isn't completely dead, but we don't seem to know what tasteful means. Some churches require their women to wear long dresses or long pants all the time (even when not in church). While I wouldn't call that dress code tasteful, it is certainly modest.
Other than showing "ten pounds too much to the naked eye" (thanks Train), there is another school of tastelessness which does saggy pants and untied shoes (usually yellow construction boots or sneakers), and then there's the ever-disgusting baggy sweat pants with slippers and a dirty tee shirt, best worn without showering so one can be smelled as well as seen.
What constitutes tasteful? Most things that middle-aged moms wear. For guys, most things that middle-aged men wear. Sensible shoes if you can find them. Jackets when it's cold. Bras when in public. Translated: stuff your kids would hate to wear.
I remember when I was an adolescent, we kids wore hip-hugger jeans (don't bend over unless you want to show somebody your Plumber's Crack), Hot Pants (double the risk), mini- and micro- skirts, bell-bottom or flared jeans with frayed cuffs and a few tears patched with anything but matching material, clogs (aka ankle-breakers), cowboy boots or engineer's boots, or bare feet, vests, tee shirts or flowery dress shirts, and bandannas and dark sunglasses. Ah, the 1970's. You haven't lived until you've seen the effect of a healthy-slim lady in a microskirt over fishnets and under a tube top. Almost anything in denim, from pants to shirts to jackets and even full-length coats and dresses. We thought we were IT in those outfits. And on occasion we showed and shocked almost as much as today's tramps do.
It used to be "cool" to be dressed in "grubby jeans."
Yes, in the 1970's, the right combination of tight or skimpy was very fetching indeed. But it's quite a different thing when skimpy clothes are stretched over rolls of fat and poorly done tattoos. It's a different thing when the message you're sending is that you really DON'T care how you look - or smell. That's tasteless, and for certain is the same thing as having a big "L" for "Loser" tattooed on your forehead.
Do looks count? Absolutely. We're stuck on this planet with each other. Some of us hire some of us. Some of us are desperately seeking someone worth being with. Dress the part, but dress with good judgment.