they kinda did that this season they added lasers to the inhib and nexus towers and added a shield that shields champs to the inner towers and for the first 7 mins the first towers take significant reduced damage.not to mention if they changed the towers the first tower would have to be easier to kill like any ad user or anyone with pushing potential could just rip through it in 5 mins or else. whats the point of it being tiny and just being there for protection and vision if its tiny that must mean its squishy and easy to kill, the 2nd towers however i do agree with can use buffs as is by the time you get to there it takes 5 shots as a squishy to get killed even if you aggressively fight under it, times by 3 for tanky characters.
i would like if towers could multi shot to prevent 5 man tower dives atleast for the first 2 towers since its kinda annoying when the entire enemy team comes to lane even tho your in a stalemate with your lane opponent and you make it to tower but everyone's there so all you can do is turn to religion and kiss your ass goodbye.