Earlier quoted context omitted.
There is immense pressure to stop online scams which are draining old people of their life savings. The whole flow from the article seems entirely based around letting power users install what they want while being able to break the flow of a scammer guiding a clueless person in to installing malware. It is promising that Google has avoided just turning off sideloading but still put measures in place to protect peopl…
Why is it on Google to stop this and not the banks?
Yes, banks should (and sometimes do) double- and triple-check with you before allowing large transfers/withdrawals, but scammers know how to coach their victims past this. Speaking from experience.
(I also don't fully agree this is Google's responsibility, and I am not happy about this development. But there are legitimate points in favor of outsourcing the question of "will this software do nefarious things" to some kind of trusted signing authority.)