I choose fourth option.
4) googles big model just performs worse than K3 and GLM so they choose not to embarass themself.
Like I love Gemini and use it a lot to one-shot whole MR with huge contexts, but its just much worse when its come to tool use and agentic coding.
or they just don't want compete in coding space ???
they have search,youtube,android,office suite like gmail,maps,spreadsheet etc
coding is the least of their problem/priority