That depends on the man.
For most 300 lb. men, a cassock does nothing at all for them in the elegance department. Priests are men, and not all men have the build and posture of the late Bing Crosby.
Thank goodness somebody has some practical sense here.
What he wears should be up to the priest, within the confines of the rules of his diocese or order.
I’m sure many heavier priests, or priests with a “hot” internal thermostat, find cassocks unbearably hot (unless they come in cooler fabrics?). But don’t they wear slacks under the cassock? For a priest who has a “hot” internal thermostat, this could be a nightmare. I am a woman, and I get hot wearing summer pajamas around the house. And I’m not just talking in the summer, either. A lot of buildings and homes are kept so hot that the poor priest would spend his life gasping for cool air.
I say the cassock of the heart is more important than the outer cassock. A cassock is no guarantee of purity or holiness.
And has it ever occurred to some of you that in today’s modern culture, many people who have never been exposed to organized religion (many Americans would qualify) would not recognize a priest in a cassock as “religious” but as “Hollywood/Matrix/Horror/Funky/Fly”, just as one of the posters in this thread observed. Nowadays, I don’t think a cassock necessarily carries the connotation of “religious” except among older folks.
BTW, we have several priests in our parish, and all wear cassocks except the older, fatter priest. I also play piano for a parish run by the Franciscans, and they wear their simple robes.