You've seen this , right? Although there say that it makes practically no difference, the context is not web but interpreted languages.
Minimization is required for code transmission. The gain is too small for the build that occurs on the client. The only reason to minify is that the source travels over the network. With WebAssembly this problem ends because the code is compiled before.
C # is compiled , so they even weigh to make a parsing , because it is more text to evaluate, but it's something tame, despicable, does not even tickle in the compiler. For the execution the comment has zero weight by all the forms that analyze since they disappear completely.
C # has other things going for execution that weigh and people do not realize it:)