Abnormal data usage in multiplayer minecraft

I am and I will always be a big fan of Minecraft. But, ever since my internet contract turned to be data limited, I lost the ability to play online, with my friends, because of the absurd data consumption.

I’ve scavenged the whole internet looking out for people that have or had the same issues, yet I can’t any answers, thus here I am, opening this thread.

In just about two weeks, playing vanilla online Minecraft on a server that was hosted on a friend’s local machine, with almost no plugins other than essentials, I used over 70 Gigabytes of data (Information based on the window’s "data usage" settings). Investigating, I tried to understand what was happening. My assumption is that Minecraft is not optimized for multiplayer. This is mainly because there is a constant send-delete-resend cycle of packages, containing terrain, mobs, their respective state, and much more. Such packages do not sound like much, but it starts pilling up since you’re constantly loading and unloading information sent from the machine that is hosting the server.

Based on this information, which I had no confirmation of, I assumed that perhaps, a skyblock approach to the game would allow me to reconnect to my friends, playing the game of our childhood. Yet, after less than 2 hours, there has been registered consumption of about 3 Gigabytes. Considering the empty chunks, I am really lacking solutions to the problem.

Is anyone aware of what is the cause of this issue? Is there any solution I could consider?

Follow-up: I ran Wireshark in various conditions in order to test Minecraft’s data consumption, double-check the packages, and look for hints to solve the mystery. The abnormal usage happens only when the host is a friend’s local machine. Using Aternos to host, or simply joining a 1.8.9 online server showed a rate of 15K bytes per second (about 50 Megabytes per hour). I looked into the packets, and I found an absurd amount of error packages, specifically TCP Dup ACK errors when connecting my friend’s local machine (boosting the rate to 300K bytes per second). I got no idea what should I do in this situation since it is beyond my understanding of networking. I can understand the error but not how to fix it.