200 riders turn off the starting fireroad at 30mph into the first bit of singletrack, which includes a very narrow rooty descent. You have the choice of stopping/trackstanding and waiting 5 minutes for a clear line, or you get off and run, when you can go through the undergrowth, and take very different ‘lines’ to the single rideable line.
You’re always going to get bottlenecks, unless you have a race of 100% fireroad, which would be torturously dull, and like it or not (I imagine not and you’ll have some smart arse justification about what girls they all are and you can puff out your chest and feel good about yourself) it may be quicker for those at the back to run.