Strip the marketing and the choice is clean. Insurance converts an unpredictable, potentially huge cost into a predictable premium: you pay every month, and if catastrophe comes, most of the covered bill isn't yours.
Self-insuring - a dedicated savings account fed monthly - keeps every unspent shekel of that money yours, excludes nothing, involves no claims process, and rolls over to your next pet. One is certainty purchased at a price; the other is risk retained with interest.
Neither is irrational; they fail in different ways, which is the actual comparison.