1. It's better than what we have today. 2. PSD2 is standardizing and increasing access to financial data, making the entire ecosystem more competitive.
Regarding #1: I understand the concerns regarding privacy and security, but this injects a whole new range of improvement that quite honestly we don't have today. Unlike many countries that have rendered their bank account number useless, the US has not. Today, we all provide our bank account numbers to a variety of companies (our jobs for salary, rent, etc.) via a direct credit or debit authorization form to a third party. The proliferation of Private Account Numberss in the digital age is exactly what's makes them such a high-value target for criminals. A digital authentication and authorization approach allows us to set parameters around authorization, rotate keys, create programmatic constraints, inject real-time security, and a number of other consumer controls (e.g. remove authorization for that annoying magazine company that charges me every month for that Better Homes and Gardens magazine I never ordered). This can all be done without providing the level of access we and banks provide on our behalf every day.
Regarding #2: Banks are great at a number of things, like holding and securing our money. They're terrible at responding to market forces or consumer concerns. Instead, they use the mountains of red tape and regulation to fortify themselves from new market entrants. Greater, more open access to financial information levels the playing field; thus, increasing both innovation and better pricing for all.
TL;DR - this is way better than what we have today.