Running it locally will always be faster as long as your machine is not a bottleneck (#cores, ram, ...). I think the use-case for distcc et al is to enable less-powerful machines to run builds faster by levering other machines. That’s exactly what we use it for at work. Our developers have not-so-powerful laptops and with distcc/icecc they can utilize the power of our build agents in the server room.
Also interesting to read: https://github.com/StanfordSNR/gg