Well, he's seen as both.

Socialism however is a post-capitalist and post-industrialization ideology in general, and the comic depicts a medieval knight and presumably medieval economy.

There are primitivist socialists but they're very much a minority. Marx specifically for example presumed that socialism would require a capitalist society that is overturned by the development of class consciousness.

You're pointing at the comic and saying "but that's capitalism" and, sure, but it's also the foundational concepts of most socialism. Socialists just disagree on who should own the machines, everyone agrees that machines make work more productive.

TL;Dr socialism developed after Smith's work and incorporates his insights even if disagrees on certain aspects