In addition to years of combatives, I'm also an NCCP Rowing coach and an NCCP2 Triathlon coach. There are no easy "gotcha" points to be had citing my "emotional satisfaction" and linking me to the generic 80/20 methodology articles. Assuming that is the motivation got a laugh at least.
With regards to endurance training there's more to it than that and requires quantifying your "time in Zone" by hours per week and allocating sessions accordingly, something I'm going to guess you don't do. Periodization of training for improvement is the whole point of what I'm talking about and misrepresenting 80/20 as "do 80% ad nauseum" is not in line with the research.
My run training had long runs of 60-90 mins, short runs 10-20mins of sprint effort, my swim training was long swims up to 2hrs (5-6km), pool sprints of 30 minutes effort total. Bike training? long rides from 2-4hrs, hill repeats? barely 40 mins. There's a pattern, it's easy to spot.
It isn't spending time at 80% effort, it is spending "roughly" 80% of my training time in a specific HR zone, and "roughly" 20% of it sprinting my face off at the track or in the pool then supplementing that training with strength and conditioning. Increasing ones baseline cardio capacity is fundamental, using high intensity efforts and S&C to train better musculature and connections are essential to become competitive outside of even local events. Training for rowing? Long sessions (90-120 mins) of low intensity technical training, and short sessions (15-40 minutes) of wanting to scream, puke and pass out. This balance is, in my experience as a coach and athlete, true for all high-level competitors.
The 80% concept in relation to lifting is not in line with the efforts of competitive lifting athletes outside of crossfit, and I'd wager the competitive ones don't do it either. I'm not a lifter, bodybuilder or a crossfitter, so I'll leave them to whatever they do.
At the end of the day 80/20 is a clumsy catch all for anything it tries to represent, in fitness it's not an exact ratio, only an approximation of periodizing intensity to allow effective recovery. It does not accommodate the cycling required to peak at multiple events through a season (or at a fight at the end of a training camp). I use it when I'm coaching because most athletes want to go too hard too often and get injured, but similarly I think it's important for someone who does it often but never hard. One will reach competition injured, the other will reach competition slow. Neither will represent themselves as well as they could have had they followed a more balanced ratio of intensities.
If you're comfortable training "comfortable," that's all that is, nothing wrong with it. Don't pretend to have tapped into the secret methodology of progress though, it mostly sounds like you half read some quick-fix lifter articles.
I asked this question because I noticed that my sparring and padwork had become what I would call a "comfortable" effort over time, and I've chosen to explore the upper range of intensity in the same controlled manner as I have done it in my other competitive outlets. You are welcome to disagree with my approach, or say it's not for you, but don't give me the "follow the data not emotional satisfaction" diatribe. Don't make me make you a spreadsheet on it bud, I did the math and I fuckin' LOVE spreadsheets.