Millions of physicists
Today, universities have produced millions of physicists. There aren't many jobs in science for them, so they go to Wall Street and Silicon Valley to apply their analytical skills to more practical and rewarding efforts.
Well, no, they have not.
Lets say a "physicist" is someone who has received a BSc in physics. Current US output is about 4500 per year. This peaked at about 6000 per year in the 60s. After BSc, the working life of a physicist is 40-50 years (depends on whether you call a graduate student earning a PhD a "working physiscist"). So total in the US is less than 1/4 million.
But, it is worse than that: as the article notes, a lot of physicists immediately quit physics. About 1/3 go to graduate school, another 1/3 work in physics related activities (and more quit after a PhD or a postdoc or two). So less than 100,000 people actually work doing physics in the United States, with maybe another 50,000 doing physics related jobs.
Sanity check: APS has a membership of about 40,000 - consistent with above numbers, and comparable to total number of PhDs working in physics. Of which ~ 10,000 (8,800 according to AIP stats) are in academia, most of the rest in industry or government.
Most of the rest of the World's physicists are produced in Europe. Enrollment % there is higher, but not much higher and declining... (cf UK's IoP has 37,000 members, though UK has ~1/5th population of US; the European Physical Society claims ~ 80,000 members, through its national member societies). And China and India are probably producing comparable numbers of physicists, but their production has only recently ramped up.
So, I think it is clear the since Einstein died 50 years ago, less than 1 million physicists have been produced by universities;
and that maybe only about 200,000 are currently working in some professional physics capacity, with probably less than 100,000 actually doing research.
Certainly not "millions". And if you want Einstein compatriots - PhD level research physicists (with or without a PhD), doing independent and original research - we're probably talking about something like 25,000-50,000 people. A lot more than in Einstein's days, to be sure. But a staggeringly small absolute number.