Critical Strike System
RNG elements are good for the game, it creates exciting moments for the player and increases variance. This means crit chance should be in the game. This does not mean crit damage should be so extreme, and one step was taken which was lower the max crit damage with Infinity Edge, but needs to be taken one more step of lower critical damage overall to focus on the system as a sustain damage system with RNG being a thing for more damage, but is not an extreme turn around point of damage.
This is what needs to happen to really bring back marksmen into usefulness, but not mandatory every game.
Critical strikes: 100% amp damage --> 50% amp damage.
Infinity Edge:
15% true damage conversion --> 30% true damage conversion
3700 gold cost --> 3600 gold cost
All Zeal Upgrades:
2900/2800 gold cost --> 2000 gold cost
Changes like these will help marksmen get their build rolling faster, starting feeling power sooner, focus their damage to burn through tanks rather than squishies, and tones back on their overall power by a lot when they are at full build and not be so ridiculously over tuned.
Since marksmen will become focused as tank buster means they are not needed every game, allowing for mages to get played in the duo-lane and opens up duo-lane options and new metas rather than default to marksmen every game. Also with crit damage toned back, you can do more to make basic attackers more unique and have things for their basic attacks to play around, meaning more marksmen and have them all unique to each other and play differently rather than feel samey to one another.