Well, I would say that just because LACs proportionately send more students to graduate school does not mean that they do better at placing undergraduates in PhD programs. Students who go to LACs might be more motivated overall to get PhDs, or the same qualities that motivate a student to attend an LAC might be the same qualities that make them want to get a PhD later.
Well, you’ve moved the bar. The first thing you said is “if you want a PhD…” that you should go to the best research university possible. But that’s not necessarily true, because the statistics point out that it’s quite possible to get into a top research university and earn a PhD by going to an LAC - or a non-top research university, honestly (or a regional comprehensive university). Furthermore, once someone has a BA and is already in a top PhD program, I see no reason why where they went to undergrad should have any bearing on their future success - once you get a PhD, nobody really cares where you went to undergrad.
That said, yes, I know successful professors at top institutions who got their degree from an LAC. It’s actually difficult to see the BA education of many professors because they often don’t list it on their webpages - just where they got their PhDs. However, I randomly chose the #5 program in my field (UChicago) and found professors who went to Williams, Oberlin, Wesleyan, Smith, and Simmons - and two of them are big names I recognize that are not in my own subfield. At Brown, there was College of the Holy Cross represented; at Minnesota, out of the five people who I checked who actually had their BA school listed, I saw St. Olaf. And it depends on what you mean by top 50, too - if you look at LAC professors vast numbers of them went to LACs themselves for undergrad.
Google has a huge office in New York and a bunch of offices in other cities too.