Old MNK was never hard. Viper is literally just that with some of the 3-hit combos consolidated to fewer buttons to make room for newer moves and a better AoE combo, plus a lot of the wish-list items that MNK mains wanted (no RNG on the 5 chakra stacks, making greased lightning not an all-or-nothing resource and not tied to ramping up speed or power, etc.). It's the reason why so many old-school MNK mains love it so much; it's the closest thing we have to a return to what MNK should have been.

Us MNK mains require an apology from the people who understand Viper, because MNK was the first melee job to be simplified into the ground and basically paved the way for the current state of melee jobs as people at the time thought it was "too hard,".
Nothing, and I mean NOTHING in this game is difficult. It's "baby's first MMORPG,". But some people are loud and effort-averse, and don't want to have to learn anything, which makes the rest of the game boring for everyone else.

We tried to warn you that the people who advocate for simplifying jobs in the name of "trying something out" never stick with the job anyway, which just ruins it for the people who were maining it at the time and had no problems with it. We tried to warn you that this would happen game-wide if you allowed the precedent in the name of "accessibility,". I'm a disabled player (have nerve damage in my right hand and am forced to play all games with a controller) and I could still do it, and everything else in the game was too boring for me. I do NOT want it dumbed down further. The number of skills being "overwhelming" to the smooth-brained is not an excuse for players to not sit down with it, read the tool tips, try things out on a dummy and figure it out. I didn't read or watch a guide to learn Viper, I sat on the striking dummy, messed around with some moves and FIGURED IT OUT, then rearranged my hotbars for comfort and now it's even a bit TOO simple for me.

The game is a terrible teacher, and the tool tips and jargon definitely need some culling and reorganizing, but the job itself - once you sit down and figure it out - is perfectly fine, if not a bit too easy. The same goes for 4.4 MNK. Not difficult, but people don't understand good hotbarring practices or how to do their positionals properly, so they whine that it's too hard for them because they don't want to think or learn. Standing in one spot until the combo ender says it's time to take a step to the left or right isn't complicated. Literally "take a step to the left and do 3 moves, take a step to the right and do 3 moves,". Too many SAM/DRG players who don't get how to straddle the SE/SW intercardinal and make egregious 90-degree rotations around the hitbox whining about mechanics they don't understand. Us ex-MNK mains know what's up.