I used to get my jeans a little greasy and wear out the jeans seat pretty fast bike-commuting in them when I was in college with 2-3 mile commutes. Road splat could also be an issue (fenders don't prevent it when a car splashes you) and getting caught in the rain was no fun in cotton. But - hey - I was just a student. I used an ankle band to keep the 'ol bell bottoms out of the chain, the calf still got dirty. The rattrap pedals also chewed up my sneaker/loafer soles pretty fast.

I am a heavy sweater. And as a Clyde-class Athena, I am more comfortable wearing compression-providing shorts when I am physically active.

Bicycling isn't easier than walking. I have some substantial hills that I struggle to summit standing on the pedals for a minute with my heartrate at 100%. After that it's still another few minutes before I finish the uphill ride. You better believe I sweat on that, especially with the hill in a humid area and summer temps around 95F at the time I ride. There is no way I would be sweat-free walking outside for 25 miles each day, either.

To the OP - just do a "dry run" on a day off from work and see how it goes.

YMMV.