I build to android quite a bit
For whatever reason the farther into the day the longer it takes to build... It is not associated with my computer (restarted it) nor the device (also restarted) but for whatever reason the process that takes a minute or two in the morning takes about 5 minutes in the afternoon....
why does unity
rebuild all the assets, and scenes if nothing has changed
I can't imagine a software as robust as Unity claims to be not taking this into account