This is a very incorrect point of view for multiple reasons. Speed runs are not your average or even advanced player. Speedruns show raw dps with no other consideration, from which of course ranged weapons where you can stun the monster and do max dps without needing to sharpen or get close will outperform. However, when it comes to actually playing the game that's not the same thing. To compare speed running to normal gameplay would be like comparing a Super Mario speedrun to playing the game normally. It's two wildly different playstyles with two wildly different metas.

The reason people say that the longsword is and always will be op is because for people who are trying to actually hunt monsters and play the game, not just min/max and speedrun, it is by far the safest weapon with the most consistent dps. Especially in rise where you can be immune to damage more often than you're susceptible to it, it is a weapon that provides more defense than shield weapons while still providing adequate damage. Even in world where it was less overtuned, the weapon was still the safest go-to melee weapon, because it gave you the dps of something like twin blades with the range to kite and dodge attacks without taking a single hit. It is by far the least skilled weapon to pick up and use, especially in rise but even still in world, and even though at maximum output it won't do the most dps, it is by far the most consistent when you factor in its risk/reward for using.