Again, did you not read the full post. I talk about the cyclic "grind":
And then I pointed out the problem, where a player with limited time can't easily achieve the high r.io score necessary to be accepted into higher keys. For a soloish player getting to a 1k+ score might take weeks (perhaps even months) but for those with a guild/community or even a pre-existing seasonal score from r.io, they could do it much faster.As a result, the general "grind" is to do several cycles of M+ dungeons and build your score up. Which normally is fine but to a player who has limited time to play, higher M+ may be inaccessible to them.