Theory vs. Practice Thread

I wanted to devote a thread to a discussion involving all aspects of bodybuilding in a theory vs. practice thread. There seems to be an over-prevalence of “experts” emerging lately followed by a huge herd of sheep claiming that the principles that were followed and worked for so many people are wrong.

I’m speaking in generalities, but here are some theories being discussed that seem to be completely contradicted in practice (i.e every truly big guy I’ve ever met contradicts these theories, and they are living practical examples)

.TBT being better than SPLITS (Covered a zillion times, I know)
.Bench Press not being an effective Chest builder
.Whole grains being hardly better than their white processed counter-parts.
.Peanut butter is bad for anybody (Charles Poliquin)
.short rest intervals during weight training being better than longer rest intervals with heavier weight for fat loss
.isolation exercises need to be avoided in new trainees

These are just a few examples, feel free to chime in with some examples of things you’ve encountered that seem to be regarded as gospel in theory, but just don’t seem to amount to much in practice.