You don't run across professors all that often. If you happen to have one or more as friends or part of your family or profession, then you do more often than most people.
Otherwise, the most likely encounter with them is when you are in college, and then you only get to know those teaching the sections of courses you happen to take.
In my experience, my college had a mix of great ones and dodos. I got some of each, but mostly dodos. That's the breaks. I couldn't afford to go to Harvard.
So after that college experience, the competence of those professors means less and less to my life. I have long since either made up for the dodo's errors and deficiencies, or their influence on me has become unimportant. The gems I received from the good ones are still valuable to me. But the important thing is that I have progressed beyond all that and it is unproductive to dwell on it. (Sometimes, though, I do think about writing a letter explaining to my alma mater why I don't send them any contributions. But so far I haven't even taken the time to do that. This diatribe may be as much energy as I will ever spend on the subject.)
But...if good professors are really important to you, I know of a good source. I can, and do, highly recommend a company that produces top-notch video and audio college courses given by really good professors. You can find them at