doctorbadwolf
Heretic of The Seventh Circle
The build doesn't require the feats to "come together", they just add to it.The problem is Evasion comes online at 7th level, and your build includes THREE FEATS. That takes a LONG time to come togther AND you sacrifice at least 2 bumps to the stats that are responsible for your accuracy, your damage, your AC (because they decided the Monk should have crappy HP despite not being harder to hit than anybody else) and potentially your Stunning Strike Save DC.
And now you're a guy in cloth within striking distance of the rest of the enemy forces with your little dinky d8 and middling CON (because you realy need to pump DEX and WIS). It's not an ideal location.
Spamming Stunning Strike on a legendary opponent is fine, but then you're basically out of ki until next rest.
The Monk CAN be good, it just takes WAY too much effort compared to a Barbarian to be just as effective, and in less generic situations. It looks simple on the surface but the ammount of system mastery and calculation of risk is just... just too much for what it accomplishes if you ask me.
And the idea of the Monk as the guy who 'locks down casters' just feels like an after-the-fact justification. A build the community came up with SPECIFICALLY to make the Monk look like a good, useful, class. Can it actually do something else well?
I've never been stuck in the midst of the enemies as a monk, unless I chose to be there (such as with my shadar-kai monk teleporting into their midst and becoming insubstantial until the start of his next turn, killing his intended target, and then soaking some damage before getting back out of there).
Regarding the part of your post replying to someone else;
Stunning strike on a legendary creature can often be vastly more valuable than dealing more damage. When it isn't, you just hit more instead. The monk has that option.
Also, the monk as anti-caster is...something that I've been seeing literally since 5e launched, so...no. It's not any sort of "after the fact justification". It's simply something the monk is very, very, good at.
None of which requires any especial system mastery. I've seen plenty of noobs play monks very effectively without any more help building than I'd give to a barbarian player.