I agree. I have constant typos in my comments here and they are definitely not indicative of my cover letters. I do not write very well on first drafts which is why I said cover letters usually take me over an hour. I usually get them proof read by my friend who has professional writing experience.

My approach is based off advice I once heard about essays for college applications. Overwhelmingly it seems like there is a formulaic approach to them that works really well. I assume this isn't specific to college admissions, but really just people in general who read lots of applications (whether it be for a school or job). Part of the advice I read was that you should stick to the formulaic approach unless you are an excellent, confident writer.

I would say my cover letters definitely show enthusiasm and I explicitly spend probably 25% of it discussing my personal interest in the position/company. But writing in a story format that is well formed, relevant to the job, and interesting is well beyond my abilities. I spend enough time as it is on cover letters that generally result in nothing.