The EU should focus on improving the business environment by standardising and liberalising the payment of payroll and income taxes across the Union (so you could work for a company in one country and live in another), digital ID, international banking, pension and national insurance transfers, and residence registration (so it isn't a months-long bureaucratic process in any new country), companies registration (to make it simple for one company to operate and hire in the whole Union, without dozens of local tax and labour law issues, etc.) and solving issues like the housing crisis, disastrous rent control schemes, etc. that impede economic mobility.