Google is a web company, why would Google invest significant money and engineering effort into filtering out things that only harm competing platforms? Google's

Google is a web company, why would Google invest significant money and engineering effort into filtering out things that only harm competing platforms? Google's own platforms (Chrome + the web and Android) are immune to this adware. It would be financially irresponsible for them to waste money helping a competitor. >If Google wants to help make the web a better place... I imagine Google thinks it is making the web a better place by investing in the web, not fighting loosing battles trying to fix old and broken platforms.