Smithing actually isnt that bad since you just buy +smelt gold at the blast furnace fwiw. Im about 1850 total on my iron right now, from my experience worst part in the 'efficent' ironman grind is probably 87 slayer or maybe the initial fishing grind (pretty optional since you can get food all sorts of ways)and the initial theiving/FM grind (,you'll be pretty poor for the early/mid game if you dont train at least one of those stats pretty high). Also crafting is a bit of a bitch but with seaweed farming and sand mining it's much better than it used to be.

Anyway my tldr answer to your question is theres many long grinds especially if you want to play efficiently but a lot of people just play ironman doing what they want to do when they want to do it and have a lot of fun that way. So dont be too intimidated, it's worth a go.