Exactly Flairon was once the best melee weapon in the game period its just that when all the other post Plantera tier weapons were buffed/reworked the poor Flairon was left in the dust. This is especially unfortunate since it looks like a normal flail and fires like the standard click of the new normal flail mechanics had it been included in the rework it could have easily maintained its position among other late game melee weapons but they didn't.
That's because back in 1.2.4 the other endgame melee weapons usually sucked.
Horseman's blade is terrible outside of statue cheese.
North pole is uh... it just doesn't work well.
Christmas tress sword was an absolute joke before 1.4.
Vampire knives were really the only good endgame melee weapon.
I guess that is one way of looking at it but on the other hand if all the other weapons got buffed were they too weak? Now some Nuance is needed for clarification that Melee as a whole was fairly weak back then and still generally is compared to the other classes not counting a certain glorified trophy.
I generally don't like limiting comparisons to 1 class, I'd rather compare flairon to other homing weapons. Based on my Empress kill times.
Razorblade typhoon is almost universally considered overpowered so we'll ignore that.
Xenopopper and nightglow are obtained around the same time as flairon and perform MUCH better.
Chain gun is considered a little underpowered and is weaker than the two weapons above but still leaves flairon in the dust.
Bat Scepter performed about as well as chain gun.
Xenopopper and chain gun never got buffs, and nightglow got an irrelevant buff.
Sadly some weapons haven't aged well spears for instance have largely been left behind since the addition of the North Pole. Short swords are now effectively Spears but able to get the legendary modifier as their attack speed and size can be modified. Boomerangs are in a similarly sad position as most neglected melee class weapons so they are probably the most overrated currently. And then there is the Phase blades/Sabers which haven't been worth using since... 1.1 Yeah.
Now that I think about it, has any spear been added, buffed, or nerfed since the 1.2 era? Well aside from the trident.
Most of the 'new' 1.4 melee weapons like flails, shortswords (starlight especially) have badass animations. Really wish some of the old melee weapons were revisited.
Yeah honestly the Vampire Knives are a bit overrated as with a good build and knowledge of what you are doing you don't need the life steal which you can't even use against Moonlord.
Everyone freaked out about valhala knight plate being op at 8hp/s, the vampire knives cap out at 30 hp/s... like seriously that's just stupid and its not hard to reach that cap. It's even better if you use it as a sidearm as if you haven't used the knives in a while there is no cap to how quickly you can restore your first 70 health.
Spectre hood uses the same mechanics and is similarly disgusting.
'You don't need it' can be applied to literally any weapon in this game, the problem is that when you do use it it's too effective. I never go out of my way to get biome keys but the few playthroughs I get vampire knives it's like wtf, how this get past like... any balance check?