tl;dr : ADCs should be the best physical damage threat on a team since that is their role's design. They are mean to take objectives and kill tanky champions efficiently. They pay for it in low defense. Tanks should not expect to last long vs an ADC because they are not meant to for the most part. They are meant to block incoming burst damage and abilities, engage/disengage enemies, peel, and use CC to protect the team and/or disrupt the enemy. Fighters are meant to be that lingering damage threat second to burst and ADCs though. They are meant for picks, and extended fights because they usually have some kind of sustain or shielding and some or multiple forms of high mobility/cc. If they are not targeted, they should deal good damage, but if focused, they should die fairly quickly because they usually have the means to escape but with lowish defense.
If we think about balance between ADC tanks and mages, then it is similar to a rock, paper, scissors match up. ADC > Tank > Mage > ADC.
juggernauts and skirmishers should be equal or even stronger when it comes to damage potential.
I highly oppose this. They should be higher than tank but less than ADC in terms of damage because they should have the tackiness to survive with the damage to kill, but not burst or heavily chunk. Juggernauts have low mobility, but also have a beefy build and can get enough damage from just 1 offensive item to kill their target. While skirmishers are more mobile but should have less defense than juggernauts because of it. ADCs have almost no defense but have very high damage and sometimes mobility. The more mobile should have less damage, or more DoT type damage (like Lucian) and immobile ones should be the highest damage dealers outside of burst mages and assassins (champions like Kog and Jhin).
there is absolutely no reason, marksmen have a higher potential sustained damage than everybody else. their benefit is already in how reliably they can apply their auto attacks.
the number 1 reason is because they have such a low defense that without sustaining, they likely would never be able to last a fight. As for allowing them to hit from safety because of range, well, melee tanks should not pose much of a kill threat to them because of their roles.
i also hate the notion that its ok for marksmen to burst the fuck out of tanks and fighters as if they were made out of toilet paper. sustained damage is supposed to be a better tool to take down beefy targets, than burst damage. but that doesnt mean theyre automatically supposed to shred them like they were squishies.
I always see this argument used. Tanks do not win vs ADC by a design and balance standpoint. ADCs are meant to tank shred by late game. Some do it sooner than others, but all do it eventually more or less. Fighters though, should also be included in this because they offer more offensive damage while also having defensive capability and mobility (often hard CC too). Tanks should last longer than fighters, but both should get out damaged by ADCs.
Maybe my point would be clearer if we look at it though a point allocation perspective.
Say every champion is given 10 points to use in their stats. And every champion has 3 stats. Damage (AD/AP/%health/True), defense (Health/Armor/MR/Shield), and mobility/utility (MS/Blink/Leap/stun/snare/Dash/etc...).
ADCs load up in damage, put almost nothing into defense, and maybe a few points to mobility/utility. Tanks do almost the inverse, while fighters balance it out between the three.
Say an ADC puts 8 into damage, 2 into mobility/utility, and 0 into defense (someone like Jhin). A tank would put 6 in defense, 1 in damage, and 3 in mobility/utility (someone like Braum). A fighter would be something like 4 damage, 3 defense, and 3 mobility/utility (someone like Vi).
Now this is not a hard restriction. Some fighters have more damage and mobility/utility with less defense than others (Divers) while some are low in mobility but higher in damage and defense (Juggernauts)
I think the main issue with strong ADCs is with the generalist ADCs (Lucian and Ezreal are the 2 big ones). They have usually no significant weaknesses and should pay for it with limited to no strengths. But items/runes tend to cover that cost when the meta is balanced or favorable (remember when Lucian was played every single game vs an Ezreal?).
got removed :DDDD
Hmm... gold buffs eh? Without the debt rune you literally won't build as fast as someone else.
They get stuff earlier you say? Funny, because I have seen countless topics about people ranting on the acquistion of wards, which IS quite hard if you even get out of lane ONCE.
ME INCLUDED have gotten wards AFTER 20 MINUTES. 20 MINUTES.
and changed other support items like 
. The only item on this list that doesn't provide something to do with shields and heals is Knight's Vow, and even then, 12% DR is nothing to laugh at. Censor and Crucible both increase heal and shield power, which stacks with Aery as well. To say that shields and heals are at an all time high barely does it any justice.
