In World of Warcraft there used to be really serious limits on how good you could make your character outside of raiding. Once you finished up with dungeons you never needed to go back, generally speaking, and once you finished a raid there was little point in returning. If you wanted to get better you threw more time into trying the boss you were stuck on, and if all the bosses were dead you could log off.
These days that isn't the case. Now you can never really consider yourself finished. The grind to maximize your artifact power is an enormous one and even though I play a lot I still haven't made it to the cap on a single weapon, much less on all my weapons. It is certainly possible to hit the cap, as I am at 51 of 54 right now, but the time investment is huge. In the next patch Blizzard is going to raise the cap again and the initial estimates are that after the 75 day setup period it will take around 1000 dungeon runs to get to the new cap.
A lot of people hate this. There is a real perception that unless you are absolutely at the peak of your ability you are letting your team down. There will be a ton of hardcore raiders who will feel pressure both internally and externally to play 10 hours a day, 7 days a week to get their 1000 runs in within two months.
This of course is hardly relevant for people a little ways down the ladder of competitiveness. That last 250 hours of grinding to get 3% more effectiveness is not in the cards for the great majority of players, and honestly they would gain far more just from the practice of playing that 250 hours than they would the numerical bonuses. Most people are going to look at that impossibly high cap and laugh.
The thing I have been wondering is how much it matters that the cap exists. If people were allowed to grind forever but the cost of each new point kept increasing then at some point people would have to say that they have done enough. The game wouldn't have a preset 'you are finished' marker and so people would stop when they wanted to. My sense is that as long as a cap exists top players are going to insist that they and their teammates must be at that cap, no matter how absurd getting there might be. They could do that now, of course, and the great majority of the playerbase does so, but the top players would have to be like the rest of us and accept that they cannot be perfect. They would have to admit that their time was a real constraint on their power level.
Having an unlimited progression scheme does have its risks though. Blizzard greatly underestimated how hard people would farm for artifact power in the early going of the expansion and that led to the first raid being badly undertuned. It was true throughout the raid but was most obvious on the final boss who simply didn't do enough. People's numbers were simply too high. The current raid is much more appropriately tuned though because Blizzard had a hard cap to work with and could tell exactly how much damage people would be capable of.
If their new cap is unachievable under any reasonable playstyle then Blizzard is going to be in guessing mode again. They will have to decide just how nuts people will be and guess at how much time the most hardcore will sink into the game when tuning encounters. In previous expansions this might have been a huge issue for the slightly less hardcore players but right now it actually works out just fine for people who are a bit behind the curve. They can just take an extra couple of weeks to farm more gear from the instance and make up the difference that way.
This is of course drawing data from the public test realm. Things are subject to change. However, it does make me wonder if Blizzard truly intended for the current system to be effectively endless and were surprised when it came to an end all of a sudden. It might be that the completely outrageous new cap is actually intended to be outrageous.
If I were designing the new cap myself I would make it endless. With any hard cap people are going to complain that they are 'forced' to get to the cap. With a soft cap they can figure it out for themselves. If each new point cost 30% more than the previous point and each new point gave a .5% increase then people would fairly quickly stall out. Sure, the most hardcore players in the world would be doing 5% more damage than me, but they would also be playing 11x as much, so that seems fine. I have a feeling that people would then just decide for themselves when it was enough. Some of them would presumably always feel inadequate if they weren't the best in the world, but there isn't a lot I can do about that. They will likely always feel that way.