Completely anecdotally: if I haven't used an app in a week then I delete it. I can't really justify it, I have 64gb of space on my phone - it's more of an OCD thing than anything else.
I'm guessing you're using an iPhone. On iOS all the apps are displayed somewhere on your homescreens. When I tried iOS that bothered me, because coming from Android I was used to being able to choose which app icons are displayed on the homescreens.
I'm similar, but instead of a week of not using it, I wait until it upsets me some way. Completely irrational, but that's what I do.