companies are stupid then, because it's obviously good for them. You're maybe thinking about how trademark lawyers pursue use of it but that's for tactical reasons not because it isn't great marketing
It would be fascinating for Alphabet to lose Google the brand to being a generic word. (To be fair, it is something that maybe should have happened already.) Kagi or DDG or someone could use a domain like google.new or google.tech to easily retrain old habits of some users. What is Alphabet going to do in that case? If Google is no longer a trademark but a generic word, do they focus on having the "Alphabet Brand Google" or "The Original Google, by Alphabet"? Either way, that's harder to market and maybe easier to build a fresh brand than fight the generic terminology.
Does the average consumer use "google it" to mean "search with Bing"?