not to be that person but imagine how stressed sakusa must have been all the time. he adjusts his schedule during youth camp so he won't bathe after anyone else. he always worries about something not being right, as mentioned by komori.
having the feeling of "I think a part of my body is unwell but I don't know" is annoying at best. it's also totally out of your control. also, really hates crowds, he wouldn't be there at all if he could help it. even if it's for volleyball, you can see his huge discomfort.