One of the main carrots for WoW players to chase is “getting better gear” regardless of the method used to chase it.
Idealistically, it makes sense to enable players to “play the way they want” in their journey to catch the carrot. Wanna raid? Dungeon? Solo? The War Within expansion has made excellent progress in enabling people to play the way they want to as an “end game progression” toward that carrot.
However, it also makes sense to reserve the very best gear for the very hardest forms of content. Working with people is inherently harder than soloing. Working with more people is harder than working with fewer. It makes sense for raiding, then dungeons, then solo content to provide the best rewards at the highest ends of the difficulty they offer.
If players can acquire the same carrot through raiding, mythic+ dungeons, or delves, they’ll do whichever content they prefer. But if any of those forms of content are time-gated in any way, players who want to continue chasing that carrot necessarily get funneled into whatever form of content isn’t time-gated (or is simply comparatively easier).
That’s content funneling.
Not all players who engage with Delves are “casual players”. They often want to hyper focus on a particular form of content until they catch the carrot, similar to what Mythic+ players are able to do. Raiding is in a similar situation. Some people just want to raid because they feel that’s the most meaningful “MMO experience” they can engage in, but the cadence of content availability forces them to be sparse “raid loggers” if they’re unwilling to be funneled into other forms of content.
I don’t think it’s bad game design to incentivize variation in how players engage with what’s available in World of Warcraft, but the incentive probably shouldn’t manifest in the form of “you can’t do this anymore” or “you no longer receive any benefit from doing this anymore”.
Strangely, PvP probably has the best “gearing carrot” of all the end-game pillars. Players can grind at it as much as they want until they acquire the carrot. As an added bonus, the “carrot” acquired through PvP has special benefits which only activate during PvP–meaning that the PvP “carrot” doesn’t infringe upon or interfere with other forms of content within WoW. In other words, PvP doesn’t “funnel” the player into anything else and it’s always available for players to have fun with. There’s even a “high skill cap” level of play available for players to chase with unique cosmetic rewards.
What if the “carrot” (gear) offered through Delves, Mythic+, and Raids likewise had unique benefits that applied only to their form of content? What if no end-game PvE pillars were time-gated in terms of gear acquisition?
Maybe it’d be interesting to reimagine the gem/rune systems explored in MoP Remix or Season of Discovery. What if each unique pillar of content dropped its own special “glyphs” (or whatever) which made the player more powerful in that particular form of content? What if players could equip one (or several) of each simultaneously?
Some examples of such “glyphs”:
Glyph of Diminutive Presence I - Unique, Passive
Reduces the range at which enemies detect you in Khaz Algar Delves by 1.5 yards.(Better bonuses available through higher tiers of this glyph from higher tier delves)
Glyph of the Bountiful I - Unique, Passive
One additional piece of gear is provided through bountiful chests in Khaz Algar Delves.
Glyph of Warring Tenacity I - Unique, Passive
The first time you take fatal damage during a The War Within Season 1 Mythic+ Dungeon run instead restores you to 10% of your maximum health.
Glyph of Warring Efficiency I - Unique, Passive
Your party’s Mythic+ timer is increased by 5 seconds during The War Within Season 1 Mythic+ Dungeon runs.
Glyph of Arachnid Frugality I - Unique, Passive
The gear durability penalties of dying in the Nerub-Ar Palace are reduced by 20%.
Glyph of Spider Sense I - Unique, Passive
Your Avoidance is increased by 2% while in the Nerub-Ar Palace raid.
Glyph of Legacies X - Unique, Passive
Your Versatility is increased by 100% while in a Legacy raid, and bosses drop 100% more loot.
There’s a lot of different directions Blizzard could go with this.
Bottom line, content funneling doesn’t need to be a thing.
EDIT: Come to think of it, Torghast had its own “tech tree” as part of its content which only benefitted the player while engaging with Torghast. That was cool. However, Torghast’s biggest problem is that it was tied to power creep in virtually every single other “pillar” of content. It’d be neat if the concept behind the Torghast “tech tree” could somehow be made into a form of evergreen content for each of the end-game pillars.