I reference mine quite often, usually for a purpose I didn't originally think of. The name of that cool restaurant in a city you visit rarely? How about how many double rainbows did you get last year in June? Pinning down dates from a previous pet. Or the funny pet photo with a squirrel in it? Where were you on March 2nd when your credit card got charged for $1202.20? When did you meet your new significant other 3 years ago or so? What trail head was it that you saw a bear? What is the serial number, VIN, or similar for just about anything valuable you own... or owned. How old where you when you won that race?
The cost of a store a photo for life isn't much, seems silly to spend hours and hours trying to delete them, doubly so because mistakes will be made. Just tag them so you can find what you want. I was surprised how much tagging helped. Grand mothers poured over ever damn photo I tagged with the grand kids. Starting collections of wild animals we've seen by state. etc. When bored I find it rather fun to relive a vacation or hike. Even my kid seems to quite enjoy "visiting" places I've been.
Sure 95-99% of my photos don't get viewed, ever. So? Why waste man hours on useless photos, just make sure you are organized enough to find the 1-5% that you do care about.