Thanks, @stevelee. I would like to clarify that I meant faster lenses. For the longer focal length lenses I was thinking of 85 f1.2/1.4, 135 f2 or 200 f2.8. Wouldn't these lenses be better than the 35/50 mm ones (faster lenses).Not really. In the f-number fraction, the f stands for the focal length, so yes, the larger f is, the bigger the opening is physically. But the denominator is the real measure (more or less) of the exposure. So an f/4 lens will give you more or less the same exposure as another f/4 lens, regardless of focal lengths. (And, yes, I realize there are a lot of yes-buts and more technical ways of saying this. But I'm just addressing main practical purposes.)
In general, you can get faster lenses in the 35mm to 50mm range than you can with telephotos. Fast telephotos are large, heavy and expensive for the most part, so somewhat less practical. And even with zoom lenses, many of them will have variable f-numbers, say f/3.5 at the wide end and f/5.6 on the telephoto side, so that difference can be built-in. Wider lenses are also more practical in low light because of greater depth of field at a given f-stop.
Also, most low-light shooting situations, other than concerts, will call for wider lenses, for example, kids playing in the family room, or a lot of night street photography.
I agree with you that composition would also play a role in the decision making process. But if IQ is the only consideration then I feel that longer focal length, faster lenses would be better due to their larger apertures.