Share your MMO roadblocks.

 Conquer Online, circa 2004-2005

Power levelling (p-levelling) was a required part of the game for high levels. Basically if you leeched up low levels, you got points you could use for something or other, I think it was access to the highest level area in the game, not sure now. Being leeched was also by far and away the best experience around. I rarely begged high levels to leech me and as a result levelled unbelievably slow compared to my peers, my highest level character was level 87, my second being level 51, both mostly trained myself at excruciatingly slow rates. I also got hacked twice, gave the account away then it got hacked again.

 Guild Wars

Max level (20) Dervish. Hard Mode was improbable with any configuration of 6 AI party members for 2 players, impossible solo.

 Maple Story

Countless classes/levels. Hopelessly limited bosses with archaic and exploitable entry systems and glitched HT, between them they have ensured that I have never seen an end-game boss in a serious run context. Mastery books were small bumps in the road, I played without the more expensive skills until I could afford to pass them, usually having to partake in merchanting to do so although these days mining is a viable if somewhat slow money-maker as well. The economy as a whole is far too easy to manipulate by hackers and people with tons of mesos, and this can easily screw over thousands of regular players who don't play the market (myself included) in various nefarious ways in less than a day of trading.

Not necessarily to do with the game itself, but a mental roadblock of mine was that you know everything you do can be done by someone richer in much less time and with less investment in emotion and they will sure as hell let you know about it. In essence if you're a regular player, virtually everything you do is worthless and you have to acknowledge that being rubbed in your face on a fairly regular basis to continue playing. That for me combined with the resulting USA-style inequality between hackers/the rich and regular players was bitter medication to take in what is supposed to be a game designed for entertainment and it stalled my own progress more than once.

Most of my problems in MMOs are social and not having sufficient connections to do things, which one could argue is the entire point of an MMO. Without connections in MMOs you're going to have a bad time. Also free2play-pay2win systems have a huge roadblock in the form of whatever currency they're charging you for built into them in any case.