Surely you must notice that "Modern American Liberalism" and "Liberalism" are two separate terms? "Liberal" can mean MANY things other than American liberalism. It even specifies in the article you're quoting. You cannot just assume that any and every usage of the term "liberal" is in reference to social liberalism, even in America it's still used in the common/typical/"original" sense frequently (just not by uninformed voters).

And AFAIK nobody said anything about liberalism (and American liberalism) and conservativism being equivalent either. "Conservative" is a significantly more broad term than "liberal" and it's impossible to definitively equate or oppose them, but generally conservativism is opposite to progressivism – seeing how liberalism is usually socially progressive, it isn't generally a perfect match. But there does exist "conservative liberalism", which is socially conservative and economically liberal – in theory what American conservatives are supposed to be, but in reality they're a bit more... fascist.

Relatively though, American liberals are significantly more conservative than, say, socialists and most leftist ideologies. They still hold many very (especially fiscally) conservative beliefs. There are plenty of American liberals that are in the pockets of big pharma.

Also calling modern American liberalism "socialism", even "democratic socialism", is laughable. Socialism requires abolishing capitalism and having the means of production belong to the workers/public. Democratic socialism is an ideology that believes that socialism can be achieved through peaceful democratic reform rather than violent revolution. Modern American liberalism specifically advocates for a mixed economy with mostly private, but some nationalized, industries, which is very much NOT socialist. It is quite literally, regulated capitalism. It also specifies that in the same article you quoted. You can't just take any welfare state (or attempt at one) and call it socialism.

For the most part, "lib" is synonymous with "so-called market capitalist and liberty advocate", i.e. almost all Americans in politics. A non-American using it to describe American politicians bought out by big pharma makes perfect sense, as most of them also claim to like the free market and (negative) freedom and stuff.