Here are a few questions to answer quietly to yourself.
1. Have you ever known anyone who got injured in distance running? Any who were never able to fully recover from it?
2. Have you ever known anyone who quit distance running before they achieved either a 100mi week or some standard of running that you would consider a minimal achievement?
3. Did you ever train on a team where everyone ran the same workouts day after day, month after month and there were very different levels of performance from this training?
4. Have you ever run with people who trained at different paces but were likely putting out the same effort level?
5. After such workouts of different paces, were there some who had more difficulty recovering?
6. Think back to the first people you ever met running. Did they all continue running as long as you did? Did they all continue to a level where 100mi weeks was the normal training method or this type of training was warranted?
Please come to your own conclusions regarding the answers to the above questions. No need to post an honest answer because that clearly is not happening in this thread.