Banks love to reinvent the wheel and definitely can't trust Google to be part of their workflow, as Google will 100% change UI or steps or rename the app or discontinue the app while replacing it with an identical one but with a different name but less features with no advance notice. Relying on Google for banking workflow means that one day the bank user support will be overwhelmed by requests like "the button disappeared, where is it now"

For the rest of stuff, this system IMHO has too much friction, the bounce rate will be too high. Businesses won't like to pay for a bot detection system (it costs $1 per 1000 verifications) that will push humans away while bots pass it without problems (either by using the accessibility workaround or by using those smartphone farms in southeast Asia)