Good games tell stories. Some of them are player driven (most FPS), some of them are lore driven (most RPG). In the former, the content is often even created by the players (see Twitch). This post will focus more on the latter.
Single player RPGs have quite a few models, but most people relate to the concepts of sandbox vs. directed gameplay. Skyrim is very much a sandbox, where you can explore pretty much every aspect of the game from the first step. There are a couple things that remain hidden until you complete X, but it’s doable. A recent article on someone clearing all the main Fallout franchise in 2 hours is another indicator of open gameplay. Doesn’t mean the content isn’t there, but it’s up to the player to participate. People are still playing it now.
FF13 is the complete opposite. Hard gates, linear story. Press A. I’d be hard pressed to say this game had any longevity, or much replayability.
Still, the general theme is that you can sit down, play, and complete the entire thing (if you have enough food/time) in one go. For a lot of games, that means that you have tons of people at the start, and then a dramatic drop off once that initial content is consumed. This is less a problem for solo games, but a very large one where you need people to play with each other.
Expansions provide a lot of initial content, but then you often see droughts between patches. Some are really good at keeping the content relevant, others a whole lot less. Wildstar hasn’t had a content patch in ages, but it still has players. SWTOR has the ups and downs, filling it with player-driven events. EQ seems to have expansions every 6 months. All over the place, really.
WoW has been nothing if not inconsistent in this approach. Vanilla had a dozen patches of content. TBC had a few, but applied a massive gating/attunement process for raiders. Extra content was a new hub late in the cycle. It was typically a pile of content, with reputation as a gate to neat items – not additional content.
MoP went bananas on that, where dungeons were a joke compared to daily quest rewards, and then what felt like 18 months before WoD. WoD, well let’s try and forget about the selfie patch, shall we? It was a massive content drought with no gating aside from garrison upgrades (which were more or less gold-making machines).
Legion was different. They had quest, reputation, and time gates on actual content. Suramar had numerous of these gates. Raids were staggered by time. Broken Shore and Argus had quest/time gates as well. It was a point where grinding provided little benefit (AP/Maw runs aside) to the new stuff. And the stuff was generally released every 6 weeks. Arguably some of that unlocked content was less fun than others. I’m thinking flying was less of a reward and more of a relief.