Meaning of "Primitive Christianity"

Why do Christian historians call the apostolic era "primitive Christianity" when from all indications they were the wisest and most robust of Christians than all Christian eras?
https://www.quora.com/Why-do-Christian-historians-call-the-apostolic-era-primitive-Christianity-when-from-all-indications-they-were-the-wisest-and-most-robust-of-Christians-than-all-Christian-eras/answer/Hans-Georg-Lundahl-1

Hans-Georg Lundahl

none/ apprx Masters in Latin (language) & Greek (language), Lund University

18.VIII.2022

Because “primitive” does not mean foolish or weak or rudimentary, primitive means “in its first state” - only very lately, since the 19th C. has the Theory of Evolution presented the “first state” of mankind as foolish, weak and unsophisticated, which is where the meaning you speak of of the word “primitive” comes from.

The expression “primitive Christianity” is older than the Theory of Evolution, and therefore than this aberration from the original meaning of “primitive.”