Originally Posted by Bob Ross

I log miles because I want to know how far I've gone...partially to compare to previous years, partially as a sense of accomplishment, partially because Going Places and Getting Out Of The House is one of the inate joys of cycling for me, and of course partially for bragging rights in BikeForum's end-of-year Annual Pissing Contest... but mostly so I can keep tabs on bike maintenance & consumables. I like data that supports "yowza, I rode over 800 miles last month, I'd better check my tires and chain!" since it's a handy reminder.




No one is suggesting you don't log your time on Zwift. Or, even better, log your watts-per-hour if "effort" (aka "work") is what you're trying to measure.
But "Miles" are a measure of distance, not "effort".
My beef with the whole Should I Log My Trainer Miles [sic]? question is purely semantic; that's the wrong word to describe what you are doing.