Lets assume that your activities represent mental toughness. Does that translate to knowing how hard you can push yourself during a set? Why would it?
I plan to answer this final part of your question as a standalone post that I will share here next week (and reply again to this comment and link you to my OP).
The "short answer" is probably yes because it allows you to go beyond muscular failure from the perspective of someone with normal intent and normal pacing issues that we all face at the gym. As a 15 second thought experiment, if you have a grueling 15-working-set gym workout and you "go to actual failure" on your first set, how do you know that your brain is not secretly limiting your intent based on the fact you still have 95% of your workout remaining?
In summary, intent & pacing are 2 things I have spent dozens of hours thinking about this year because it seems that most pop-sci influencers (such as Jeff Nippard) seem to treat the concept of pacing/intent as less interesting and less important than the main hypertrophy concepts (which is true, admittedly) but pacing/intent are the 2 topics to fitness which I find the most interesting. I love asking myself "why did I reach muscular failure"? Could I have tricked my brain into forcing 1 more rep by manipulating my life story temporarily so that my brain believes that my entire life has been leading up to this 1 singular moment?