Internet/Mobile data limit(s) question

When it comes to internet, we have data limits, same with using the mobile data on your phone. I know we can modify the hosts file in windows to redirect all connection attempts (for example) to youtube to 0.0.0.0, therefore leading nowhere. and for the netguard app for android, that seems to work somewhat like a hosts file, preventing apps from accessing the wifi/mobile data at all while its active (by vpn filter redirecting)

What I don't understand, is while using netguard to limit apps using mobile data, and using the windows hosts file to redirect website connection attempts to nowhere, will any failed connection attempt as mention above still use up data for wifi and mobile data, causing us to hit our data cap someday? or will this not count towards any data cap, saving us money in some aspect of a long run

Now I've tried this experiment trying to log in my facebook account in my facebook app after reaching the data cap. Even though it fails to log-in, it still consumes a bit of data according on my phone.

My own guess is no. As long as there is a connection attempt then it will still consume data.

Let's hear what the others would say though.