I cannot disagree with what you've said. cybpsych below you has summarised it nicely - there is no perfect solution.
However, it does not mean you stop looking for improvements. To cybpsych's point, you need to strike a balance between security and convenience, and I think based on the volume of scam calls going around right now, there is certainly a need to beef up security, and I don't think it is at all unreasonable that we are expecting some improvements/changes.
This is a constant cat and mouse game, but if you're going to just give up and say "humans are the weakest link" (despite this being true), then you're constantly finding a reason to not improve... and to be honest, from BigPay's perspective (as a business), this is probably fine until you have a nimble/agile competitor who is constantly listening to their consumers. But for BigPay, they're still unique in the market, so they don't have a strong incentive to improve/change things. Who else are we gonna start using if not BigPay..? No competitors here.
Increase tax on alcohol? Either you can see that as, you're just making those that drink alcohol poorer, or, you're disincentivising consumption by making it more expensive.
Summary: There are always two (or more) ways to look at things.
Hmm..... maybe don't use whatsapp? My friend who doesn't use whatsapp don't get such scam calls.