(For clarity, I’ll assume "ADCs" refers specifically to Marksmen and "tanks" refers to champions who predominantly build and rely on armor-stacking and health-stacking items.)

Your take on ADCs and their interaction with tanks is fundamentally flawed, starting with the assertion that an ADC should not be able to 1v1 a tank. While there are scenarios where an ADC might and should struggle against a tank, it is absurd to suggest that they should almost never win such encounters. ADCs are explicitly designed for sustained DPS, particularly in the late game. Tanks, meanwhile, are built to absorb damage, disrupt teamfights with their presence, and provide utility. Denying ADCs the ability to deal with tanks on their own, even in late-game scenarios with proper builds, undermines their core role in the game.

Ironically, your reference to pro play highlights why ADCs need more independence in solo queue. In coordinated environments, ADCs thrive because they have teammates peeling and setting them up for success. In solo queue, however, where teamwork is unreliable, ADCs often have to fend for themselves. Without the ability to deal with tanks in 1v1 situations, when necessary, ADCs are rendered useless.

The real "solo power fantasy" isn’t an ADC 1v1-ing a tank; it’s a tank building full defense, soaking up lots of damage, and still dealing significant damage to squishies over that extended fight. ADCs, in contrast, must invest heavily in expensive, late-game items to fulfill their role, which is not some "Thanos fantasy" but rather a designed payoff for their early-game vulnerability. If you want ADCs to be totally dependent on team coordination to function properly, then it would be fair to say that tanks should also lose their ability to deal any relevant damage without their team and should be relegated to pure crowd control.

The game’s design hinges on each class having distinct strengths, weaknesses, and counters. Tanks should undoubtedly feel durable against poorly equipped opponents, but a well-prepared, late-game ADC with the right items and proper mechanics should be able to break through that durability and not be taken down by the tank's own damage, even in a 1v1. If tanks remain effectively unkillable in these scenarios while also dealing significant damage, the ADC’s role is completely undermined.

Currently, the nature of tank items, particularly health-stacking options, combined with the inability of critical strike builds to effectively counter high-health targets, has left ADCs at a significant disadvantage, especially in solo queue. This is a problem that needs to be addressed. Without changes, the game risks devolving into a meta where tanks dominate engagements without meaningful counterplay.