Who has said this? I think most here said that they base their training off of a TR plan, just that they add endurance and outdoor rides as necessary as well as alter the plan to accommodate (planned and unplanned) circumstances (e. g. holidays, work-related trips, sickness).
How would that work? To whom should I be compared to, people of the same gender who had the same or similar W or W/kg last season and are in the same age bracket? How do you take other factors (sleep, quality of nutrition) into account?
And even if you could, does that generate good incentives? I personally doubt it. Especially people who are — statistically speaking — below average could be really discouraged from even training. I think it would be incredibly disappointing if I am told I should expect X gains and I only achieve X - 20 W. Outcome-oriented goals are poison in my experience. Instead, people should learn to embrace and enjoy the process of training.
TR has had this for as long as I am using it: go to the calendar (e. g. on your TR athlete’s page) and look at the right. You’ll see TSS per week. At the top you see a bar chart with TSS/week. You can clearly see the TSS ramp. Note that since TR adopted AT, it no longer ramps by TSS. Still, TSS ramp rates will give you some idea, though.