The number of US consular officers is fixed, is finite, and is very small. There are 8,000 total US Foreign Service Officers in the entire US government. That number includes all administrative, economic, political and cultural affairs officers as well as consular officers, and many of those consular officers deal full time with American citizens’ services, not visas.
During FY2019 alone, the remaining officers issued 8,742,068 nonimmigant visas, found 3,742,047 applicants ineligible, then overcame and issued 830,177 of those initial refusals*.
During that same time, those officers issued 462,422 immigrant visas, refused 298,017, then overcame and issued 177,902 of those refusals*.
This is why a nonimmigrant visa interview doesn’t and can’t involve a leisurely heart-to-heart interaction. That, and the law that states that every applicant must be considered an intending immigrant unless that person can convince the officer that s/he is not.
*The refusals that are overcome are attributable to incomplete or erroneous applications that are later corrected, and those placed temporarily in administrative processing for various reasons. Every case that is refused and then overcome requires at least four times the interview time.