Can any public sector HR weigh in on why their offer processes take so long?

Worked in an MNC prior and I received the verbal offer + completed verbals negotiations within 2-3 days. Their clearance for the salary negotiated was almost immediate. Next were the background checks which took 3 weeks as they hired an external party who hunted down every past employer - props to them, and I understand why it had to take that long.

I’ve just gotten a verbal offer from a stat board and (according to HR) background checks are completed, salary clearance is done, and we’re only pending the formal letter.

HR stated that it should take around or more than two weeks for the letter to be written. Can any gov HR chime in on why this is the case? Don’t most letters come from a template with fixed variables?