organic chemistry - Why can't antiaromatic compounds just escape planarity and become non-aromatic to avoid destabilization?

Why can't just all anti-aromatic systems lose planarity (and hence conjugation) and be non-aromatic like cyclooctatetraene ?

Would they not be more stable that way? Because anti-aromatic systems tend to be highly destabilized.

What can be a good working rule to predict whether an anti-aromatic system will remain anti-aromatic or whether it will somehow manage to lose planarity and become non-aromatic?