[BjoernKW]

It's a reasonable approach.

From my perspective it's not so much about the "retire early" but rather about the "financial independence" part. Even if you don't intend to retire early approaches like FIRE are extremely useful for establishing or restoring financial sanity.

If you think about it it's really not (or at least it shouldn't be) all that novel an idea: Consistently spend less than you earn.

It's just that industrial societies at large have become used to a rampant consumerism that favours spending more than you earn.

More traditional retirement plans also disproportionately benefit banks and insurance companies.