Main summary of video:
Make ADC offensive abilities scale with champion level (total attack damage ratios). Essentially, he states how champion abilities should be scaled off of total damage and how items (specifically zeal items) have attack damage. This would allow ADCs to have a progressive powercurve where, as an example he gives about Tristana, her E at level 9 is no different than her E at level 13 as that is the period where she would buy a Rapidfire Cannon. Now, there would be changes with the items as adding more damage would be added for the loss of attack speed/crit chance. This would lower the DPS of ADCs but allow them to be not only feel more balanced, but feel better to play.
He further explains how champions with total attack damage kits that also build items that have attack damage have smooth power curves (not going from completely useless to suddenly hypercarry status), an example being Lucian who feels as if gen has agency the entire game and doesn't stay irrelevant until he gets items under his belt.
Champions that are auto-attack based also feel the same gampeplay-wise. You sit there, click, and kill them. Ashe, Tristana, etc. are examples of this. For Ashe you W/R when it is up and AA the enemy to death. For Tristana you W away to AA the enemy to death as well as using R to create distance and time to AA. Champions like Kalista and Lucian feel better to play as they are more mechanically intrusive rather than the one two, buckle my shoe, three four, I'm auto attacking you to death.
Just wanted to talk about ideas for ADC changes, as I feel these propositions would be much better than the current situation of many ADCs.