For me, Sweat washes off. Deordorant is good stuff. I hate being cold so getting warm is fine. Why shower just because it's a scheduled activity; better to shower because I need to wash sweat off.
Running is a special case... I like a challenge. I was (am) always the slowest & weakest but I still have that childish thing of enjoying the achievement & satisfaction of knowing I worked hard and did something that was hard for me -- I don't care if others can do it better, because it was hard for me and I did it anyway. "Just because something is difficult is not a reason not to do it".
I am a terrible runner. So the fact I can go out & run miles (slowly) is amazing. I am so happy with myself for 12 minute miles.
My favourite types of exercise either involve exploring (kayak on rivers, walking up new hills, cycling in new places or seeing what's happening in old places... ) or utility (walking & cycling to get from A to B or to exercise the dog). Digging the garden or DIY can be quite physical, too.
Oh, and runner's high. I am sure i get that, too. It helps.
Other people want social exercise or like private youtube routines or something meditative. Only some exercise freaks want to brag every event on Strava.
You get to eat more if you exercise more. I lose my appetite if I don't get any exercise, so I have to exercise if I want to enjoy food. Most women my age are fat. I am not fat. No magic genes, no diet, no natural athleticism to explain that. Life long exercise habits are main reason I am not fat.
I could flip your Q around & say how can anyone enjoy just sitting around all the time. Haven't you seen everything on TV three times already. I don't want to feel creeped out by lurking diabetes, visceral fat, hidden heart disease, risks of cancer...