As you typically progress through RPGs, the different towns you unlock have completely new inventory in stock. Sometimes you can find items in dungeons via exploration, but sometimes crucial items can only be purchased. Shopping in of itself isn't as much of a distraction until you're trying to remember where that one shop was that had that thing you really need. However, you have to admit that one of your first steps when you reach a new town is to check out their wares.
Mining isn't in too many RPGs, but when it's there, it will take over your time in a way you never thought possible. Take Mass Effect 2, for example. I know I spent more time mining planets to depletion than doing any other side quest. If there was a planet out there to be mined, I was going to mine it. I spent so much money on mining probes it was ridiculous. I regret nothing.
Fishing is either the worst mini-game ever shoe-horned in to a RPG, or it's the most addictive. It's crazy how it's never somewhere in the middle. I have a friend who has literally bought games just because she heard the fishing was fun. Nintendo is often the king of incorporating fishing into their RPGs for various reasons, but several PlayStation RPGs also include fishing, such as the recent Star Ocean Integrity and Faithlessness and the upcoming Final Fantasy XV. In FFXV, the fishing does more than level up Noctis' proficiency for the task, it also gives Ignis new ideas for recipes.
Alchemy is typically a feature in western RPGs, such as The Witcher 3, Kingdoms of Amalur: Recknoning, and Elder Scrolls V: Skyrim. Getting hardcore into alchemy is often optional, but there's something about putting together your own potions on the fly instead of buying them that is often more appealing. When I upgraded my herbology specialty in Dragon Age: Origins, I nearly did a victory dance that I could mix high level potions out on the field. Which brings me to #6...
Harvesting or gathering herbs was my downfall in The Witcher 3. It was nearly my downfall in Dragon Age Inquisition. It's already a huge distraction in Star Ocean Integrity and Faithlessness. I know that I'm supposed to go that way to fight the mini-boss, but there's a green light shining over here. There could be something I need to create a potion or trade with a merchant or simply eat! I can't ignore it, not when it's right there staring at me. Sure, I might have 500 elfroot on my person, but I don't have a problem.
Why bother with all that gathering and mining? It's so you can craft things later! It's often cheaper to craft your own gear instead of buying them at stores, and sometimes crafting is the only way to get certain gear or improve it. It's easy to spend so many hours crafting gear so you can craft other, better gear. People love crafting in games so much, Notch made a fortune from creating a game solely about crafting.
There's no decent RPG out there without treasure boxes to open. How many times have you completely diverted your path because you saw a glimmer of a treasure chest out of the corner of your eye? Or retread dungeons looking for any chests you might have missed? Those chests could contain that one material you need for crafting, or a rare accessory that you can't find anywhere else. How could you not go looking for all of them?
You can't find those treasure chests, rare herbs, rare materials, or rare enemies to kill for their rare materials without exploring. When an RPG has an overworld map blacked out with regions you haven't discovered, you just have explore them and see what riches they contain. Exploring is how you get s**t done in RPGs, whether it's with grinding or our #2 on the list.
Item farming was almost the number 1 distraction on our list. I know for a fact I spend more time seeking items from enemy drops and harvesting for potential crafting than I do playing the main campaign. Can't tell you how many times I'll find a recipe for an item and then run through a certain area over and over and over until I get the item drops I need. Finding all the items needed to open Whimsyshire in Diablo III was particularly time consuming. Fairly certain I took more time farming for those than I did playing the game all the way to level 60.
Side quests are by far the most distracting elements in RPGs. Sometimes a side quest will be pertinent to the overall campaign, but more often than not, the side quest is a complete waste of time other than getting some XP and perhaps a rare item for crafting. It starts off simple enough. You'll stroll into town, meet a guy with a harmless fetch quest, spend three hours doing said quest, and then forget why you came to town in the first place. The struggle is real with side quests, as well as the struggle to not do them.