Devs switch because all of the magic of "AI" is LLMs + we stole the entire written output of the entire human species, with some remaining % coming from various tricks we've learned over the last 3 years like thinking and agent-toolcall loops, which weren't hard for literally everyone to copy. One of the consequences of this is that the only thing that really distinguishes anthropic from kimi is that they have the entire US VC market funding them because they promised to finally put white collar labor in its place.