I thought that perhaps a way that you could do this would be to alter the way that you implement the 5 minute turret fortification
The reason that turret fortification exists is that a bunch of pros figured out that the best way to play the game is simply to trade both bot and top lane outer turrets and funnel that gold onto your ADC, so your ADC effectively starts the game with 3K gold instead of 500. What a world. Being that it made the game incredibly stale and unfair to watch, Riot implemented fortification so as to keep teams from simply turret trading, as the team that went bot would always have the faster execution and rotation.
For those that don't know, for the first 5 minutes of the game, top/mid turret have a passive called "fortify" which gives 50% damage reduction from all sources and is applied before resists. As a result, you dont deal damage to top/mid turret for the first 5 minutes. (level 3 darius has 71 AD. Meaning that he deals 25.3 damage per attack (71/2*0.71 which is the 50% damage reduction [which means that you take half damage, 100% DR would mean you are invincible] and then the 29% damage reduction from the turrets 40 armor) Darius' attack speed at level 3 is 0.634. So not accounting for minion damage, because minions do absolutely no damage to turrets in top/mid pre 5, it would take ~40 attacks for Darius to take 1 plate, which at his current attack speed would mean that he would need to hit the turret for 62 seconds straight (which isnt possible) If you add minion damage back in, I'd say that you could narrow that down to 45 seconds, and if the Darius is running demolish and weaving Ws off of CD, then maybe it goes down to 38 seconds, at best. (demolish deals bonus physical damage which is reduced, and it scales off of max health, so level 3 darius would deal 355 damage normally, but it gets reduced to 126 damage.
So as a top laner, it is impossible to get a kill and then take a turret plate before backing if the game hasnt reached to 5 minute mark yet. Compare this to a bot laner, who has the possibility to get a level 3 double kill, turn that into an easy plate and then back. So ~400-500 (kill and minion) gold and an XP lead compared to ~900-1000 gold lead (kills, assists, minion, and plate gold) and an XP lead. You can see why, besides drags also spawning bot lane, and traditional ADCs scaling harder than any other class, most teams want to put priority bot lane; it simply gets you the most bang for your buck.
Heres how you could change fortification so as to allow more top lane agency while also stopping pro teams from simply trading turrets; **Get rid of the current 50% Damage reduction for the first 5 minutes. Instead, replace it with a passive on the top/mid turret that grants 50% damage reduction IF more than one enemy champ is within turret range or 800 units.** This way if a player in a solo lane gets an early kill and wants to push that into an early plate, they can. But it stops teams from simply grouping four members and trading turrets.