“Truth” in the most practical sense is whatever most people believe and espouse.
Sure we’re all more sophisticated and intelligent to believe the actual truth, but do you have the willpower to fight that battle every day?
You espouse this like a rule but it just isn't so. Nazi Germany believed themselves to be the righteous rulers of the earth, descended from Ubermen that never existed, commanding more powerful armies than anything, and were allowed to live that delusion right up until the democratic world forced them to reckon with reality. You can avoid that reckoning for arbitrary lengths of time.
It's no different to "the market will remain irrational longer than you can stay solvent". It's the same rule. Reality can be avoided for as long as you want if you don't have infinite ambition.