Little known fact but almost all “US spelling” came from Britain or was derived more directly from Greek (s/z). Also some incursions from French were dropped. Further, it was the British that changed during the 18/19th century in accent and spelling, around the decline of the British Empire.

So avoiding the differences on purity grounds is not particularly logical.

Not forgetting Noah Webster - https://en.wikipedia.org/wiki/Webster%27s_Dictionary#Noah_We...

Indeed, from that paragraph:

"He was very influential in popularizing certain spellings in America, but he did not originate them."