Anecdotally, O365 products always felt like disjointed attempt by various engineering and sales teams to put a modern spin on the client side offering. In these contexts, it never had to be good - but just similar enough to the old products that excel, word, and outlook power users would use it and find value.

GSuite, Notion, Confluence, and others appeal to an audience that either never required MSFT office nor felt the need to become power users in it.