Comment by jacquesm

Indeed. But the devil is in the details and many networking protocols have layer upon layer of fixes to ensure that things normally speaking go smoothly. Depart from the beaten path and you are most likely going to find some of your assumptions challenged.

One of the more frequent occurrences is the silent fragmentation and re-assembly of packets and/or the attempts to transmit packets that exceed the MTU. These are all but guaranteed to lead to surprising outcomes and much headscratching.

A name like send_but_make_sure_you_read_the_documentation() would have probably been more appropriate but it's a bit unwieldy, and in the default case it is precisely the silent activation of various algorithms to fix common problems that allows you to get away with calling it 'send()' in the first place.