Hello
On a query like the one for which you provide data compression could only have a negative impact. It seems that all the data is in the cache (disk read = 0) & Elapsed time = CPU time.
For compressed table CPU time will always increase, as the data, must be uncompressed to be processed... Nothing to do about that... except perhaps uncompress the table.
If the query had to read the data from disk compression might have a positive impact as the data to be read would be 2 time smaller and might have balanced the time lost for uncompressing data.
Judging compression impact focusing on one select statement might not be very representative.
Best regards