Screenplays have gotten shorter in the past half-century or so. A modern screenplay averages 100 pages in length, and a sign of good writing now is leaving plenty of "white on the page."
It wasn't always so. In the '40s, as talking pictures began to hit their stride, screenplays were rather lengthy and wordy, or at least they would seem to be by today's standards (I don't have any screenplays from the earliest talkies, but I might update this later if I get my hands on one).
This Preston Sturges script for The Lady Eve clocks in at 200 pages. Now, it's a shooting script, so it contains scene directions and other things which wouldn't be in a spec script, or even an earlier draft. But it's still fairly representative:
The sluglines look different, but otherwise the formatting is still basically the same. The major difference one notices when reading a Sturges script is how detailed the scene descriptions are.
In Chinatown, we see something much closer to what we're used to. Again, this appears to be a shooting script, so some of the scene description is allowable in a way that it wouldn't be in a spec, but still, it's very, very detailed: In case it's too small to see, the paragraph says, "Gittes stares at her. He's been charged with anger and when Evelyn says this it explodes. He hits her full in the face. Evelyn stares back at him. The blow has forced tears from her eyes, but she makes no move, not even to defend herself."
In a contemporary script, 40-Year-Old Virgin, we have scene description in its current incarnation :
This is what is now considered an acceptable amount of prose on a page.
I'm not sure I have an opinion one way or another -- I'm a skimmer rather than a reader myself, so I actually enjoy not having to read a lot of description -- but I just find it interesting to chart the evolution. There's a fine line between overwriting and trying to get a prose style to convey your story ideas, and the line seems to be getting finer and finer, as we strive to use the fewest words possible. It kind reminds me of the old joke, "Brevity is ... wit."