Can too much wattage on a charger destroy my iphone 7 plus? I've been googling it and trying to find answers but I cant find a direct yes or no. All I find is "My 12w charger works on my iphone" and "iphone draws as much power as it allows so its ok to use an ipad charger" and "read the manual to be sure" 

Well I saw a 50W charger on amazon. 

Thats like 5x more than a 12w charger. And it was only 25 bucks. 

Will a 50w charger destroy my phone?
As long as the charger is standards compliant, your phone will not be damaged because of the wattage. The phone and charger makes sure that the phone does not receive more power than it can handle.

The 50W charger you saw on Amazon is most probably misleading you. There's a bunch of these advertised as outputting "up to 50W". The reality is that the chargers have multiple outputs and each output only supports up to 2.4A per port - which at 5V is 12W.