"Professor" and "researcher" are synonymous at American research universities. I've worked for two world-famous research universities. Getting tenure is insane

"Professor" and "researcher" are synonymous at American research universities. I've worked for two world-famous research universities. Getting tenure is insanely difficult, and has approximately zero to do with teaching ability. (It's different for adjuncts, lecturers, others who are hired to teach. But they have different titles.)