This seems to be the generic pro-LAC statement criticizing any non-LAC college or university. It is not really accurate, despite it being the apparent conventional wisdom (at least among pro-LAC posters) on these forums.
The actual reality of big research universities is that large classes will typically have a faculty lead instructor doing the main lecture, which can be very large, with discussion sections and labs (if applicable) run by PhD student TAs. So, of course the student sees the professor in the lecture. Seeing either the professor or any of the TAs outside of class can be done at their office hours (most accessible at times other than right before or right after an exam).
A student may still prefer the LAC model of instruction over the actual research university model, but it is important to compare with the actual research university model rather than an imagined one.
Medical school admission rates are not really comparable across schools. Wellesley and Barnard both have pre-med committees which write committee letters for pre-meds whom they have pre-screened (those whom they believe have low chance of medical school admission will be advised to take alternate career paths). UCB pre-med is basically a free-for-all.
Attending a college with a pre-med committee can be advantageous to some students – being “weeded out” by the pre-med committee means that you can switch career directions earlier rather than wasting lots of time and money on futile medical school applications that you might do in a free-for-all environment. But it is important to note that pre-med committees do make medical school admission rates look better because of this “weeding out”.
Pay levels after graduation for students who received federal financial aid vary by major, and are mostly not that different between Wellesley and UCB, although Wellesley has more majors with insufficient data (presumably due to its smaller size).
That said, a free ride to Wellesley is hard to pass up compared to spending $130k at your other choices.