yitzchokm- it has nothing to do with modernizing. It has to do with that metzitzah bapeh might be more dangerous than metzitzah bakli (which is equally archaic yet no one wants to stop that), and since there is no source that metzitzah has to be done with peh, there is no reason not to do it the safer way.
“because we are now “enlightened” and understand and now know better then our forefathers?” some could argue that Chazal, the Rishonim, and early Achronim (the forefathers I assume you mean) were not as advanced in science and medicine as we are (I’m assuming they would have had no problem smoking as many of our gedolim in previous generations did before it was medically proven to be dangerous) and were unaware of the potential dangers in metzitzah bapeh.