Leaving aside the political aspects of Brexit, for better or for worse the EU and the UK are now on different trajectories. There were significant differences before Brexit, of course, but now the gap is widening. This is true in technology just as much as in other areas of business and commerce.
FinTech in particular is at the sharp end of regulatory differences between the two territories. In both the UK and the EU, the legislation underpinning the open banking aspects of FinTech is the Revised Payment Services Directive (PSD2) which came into effect in 2016, the year of the Brexit referendum vote. But there the similarities end.