"To save money, reduce expenses"
It's much easier to write better essays when you care a lot about something, really want to make it convincing and spend effort polishing your technique based on actual reader feedback. Even the "form" taught at school doesn't really matter because different audiences and topics require different arguments and require you to focus on different details, so the best kinds of essays often look nothing like say full score GRE writing test essays.
Of course there is no one true best form for essays of all kinds, so in some cases a less common structure should be used. Even then, at least a familiarity with some of the most common high-level structures of introduction, extrapolation, and conclusion can provide a starting point for adapting that basic style to the circumstances at hand. In the same way a pianist studies scales early in their learning not because scales are beautiful music, but because it provides a baseline of skills that can help them to make beautiful music upon.
A finer point: the five-paragraph essay that was popular -- no, required -- in my 90s-era American high school is a great format for creating forgettable text. It's a succinct recipe for making an outline slower to read. Thankfully, we have ChatGPT for that now. But still, real writing can aspire to something more visceral, or raw, real, or just damned interesting.
(For the record, I had excellent English teachers... but the tyranny of the prescribed essay spares no one. No slights, Mr(s). Neely, Vosovic, Dewar, and Green!)