You know.....you're not wrong, not entriely at least.
Because Riot does always buff marksmen, or at least a few of them, any time any other class grows so strong that the marksmen are suppressed by it.
But marksmen don't have it easy either you know?
Any half decent ADC would know that the support is the entire reason they can exist botlane, they will praise their supports like they praise the sun in dark souls.
If they don't then they really do deserve to get roasted, and i am speaking as someone with both marksmen and supports at lvl 7 x)
And while i have played with bad players on both sides i have also played with plenty of good people too, who realized the importance of their role or how much work i put in to keep them safe and steady.
And while i do understand your frustration at marksmen being enforced i do want you to consider this, if marksmen weren't around everyone would probably be playing skirmishers like fiora, yasuo and...tryndamere? Kayle?
Because the marksmen are the strongest counters toward those who are so extremely hard to shutdown with burst.
But marksmen are also the greatest reason supports exist, without them the general healer or peel support would be less relevant and instead you´d go for duo mage botlane for CC and burst chains.
Tanks would be fairly bad too, after all their resistances would be nerfed so mages can hurt them and then they´d be pointless. Not to mention how useless they are anyway against Fiora, Darius and Trynda.
Assassins also generally profit from marksmen existing, because they and the supports are the most favored targets, mages generally have stuff like
or powerful CC or other self preservation or just massive range to keep them safe.
So the remaining ones would be skirmishers, juggernauts and mages, the others would remain to some degree but they´d be far weaker in comparison.
But are people wrong to be frustrated? No.
Because it's often true that the botlane that wins will snowball and be able to carry games, many play that role as a duo which is far more potent than any other combo.
And isn't it frustrating then, that two people out of 5 can keep a game going even if the others players on the same team were smashed?
It is really, i won't argue otherwise.
But it's also unfair to make judgement and statements about marksmen based on their snowball, please do consider their base points.
I really think it's kinda unfair that everyone keeps calling
and
OP when it's
and
that have dominated for so long.
Instead it's all thrown under the same banner and suddenly all marksmen are OP and bullshit even if their win and playrates aren't even good.