your bandwidth has very little to do with how laggy a game can be. there are many factors.
for one, the further your opponent is from you, the longer it takes for the data to travel. EC to WC connection is generally not recommended.
then you take into consideration of your ISP. you isp may have a lot more “hops” than the average ISP, when sending data. basically what im saying, your isp could be sending the data through a longer route to travel, causing more lag.
are you cable, dsl? what? if its cable, you could be trying to play at peak hours when everyone(who also have the same ISP) in your area is also downloading and such. cable users share bandwidth. its usually not a problem these days.
if its dsl, how far are you from the ISP’s local node? the further you are, the worse it gets. you shouldnt be more than a couple miles away
another problem could be the wiring. do you live in an old building? the wiring in the walls and outside could be old as shit.
then the router and modem, you using generic shitty brands or very good brands? are they setup right? are the cat 5 cables not too incredibly long? as well as the coax cable for the cable modem, if thats what you have? do you have computers on the same network that are active when you play? i.e. torrents, streaming videos, downloads, uploads, extensive web surfing, etc…
is your router wireless? is it secure? if not, someone could be tapping into your connection and stealing bandwidth.
now after all this, you gotta factor all these things on your opponents side. now you can see how messy all this can get.
keep in mind too, 3s netcode on live is not the greatest either.