A nice mechanical keyboard is nice, especially to touch type on. It's only going to improve your writing in the sense that you'll be in a better headspace when you write because you're using a nice keyboard, but then how many hours a day do you spend typing? Is it not worth spending them typing on something you actually enjoy using?

The quality of a photographer may be independent of their camera but I guarantee professional photographers don't use cheap shitty cameras.

Edit: Tradition dictates a car analogy, so - when I bought my first car I couldn't understand why people thought disk brakes were better. I mean, you can lock the wheels with drum brakes so they're equivalent, right? Then when I got my second car with all-round disk brakes I was retrospectively horrified that I'd ever trusted my first car's brakes with anything.

Of course, a year later when I was more confident and started testing the limits of my second car, I found out the difference between disk brakes and racing brakes...