A quick raging thread about marksmen
First : the mechanic of the class itself. Main source of damage doesn't require cooldown or ressources
Second : damage dealt. Poke mage have low damage on spell because they can spam things from a safe distance, but still have cooldown and ressources to manage. Marksmen can do the same, while dealing an insane amount of damage, not having to aim.
Third : life-steal, imo the most unfair mechanic. Spell-vamp got removed from mages because "being able to drain-tank is unfair".
as fair as I remember, this item always existed, and the sustain it provides is just stupid. During teamfights, if you don't one shot the ADC, he's just going to hit you with 3aa and manage to reach 60% of his hp.
Fourth : self-peeling on most of them. For a "high-risk, high-reward" class, the risk is almost inexistant for most of them. Let's also not forget that the support is more like "supporting the marksman rather than his team", with insane tools
W+R+range
E+W+range
R+E
W
perma slow + R
E+
E
W+E
And I can keep going about it.
Fifth : it's the most polyvalent class of the game. They can : wave-clear
, siege, main source of damage during teamfights, splitpush
THEY do have some weaknesses, but most of the weaknesses can be completely ignored thanks to their support, their self-peeling, or the allowed itemization to them

OK, this is a raging thread, but this is what I've been thinking about this class since the beginning of this season. They used to be balanced, but I can't remember having a game without a marksman.