Use TEXTJOIN instead of JOIN
TryTEXTJOIN* TEXTJOIN(unlike JOIN) can skip blank values by setting its ignore_empty argument to TRUE or 1:
=textjoin(" vs ", 1, C10:C14) =textjoin(" vs ", TRUE, C10:C14) The second parameter is set to 1 indicating that empty cells should be ignored. Zero will include those empty cells.
* When TEXTJOIN's ignore_empty argument is 0 (or FALSE) it behaves the same as JOIN.