The amount of things wrong is impressive

You're confusing Europe and the EU

You're forgetting about Ireland and Malta

You're thinking that because the UK left the EU it will change the main language countries use to speak to each others

A language is a tool, not a nationality or a border.

Your average educated European speaks at least three, one of which is English because it is a good language to have because it is the language of international commerce. This has been the case since many decades and has nothing to do with using the language internally.

But: many people do use it internally. French tourists abroad are more likely to use English than French. European colleagues usually standardize on English, both for their communications as well as for their documentation needs.

Scientific literature is predominantly in English (at least, for now).

So there are many reasons to use English which have nothing to do with allegiance or dependence.

The UK did not leave Europe. Just the EU. But also English fluency is widespread, so it’s not a bad starting point.

It has been around 300 million years since the UK drifted away from continental Europe but it is still very much part of it!

Ireland and Malta.

You would be shocked at how well certain nationalities like the Dutch and Swedes speak English.

The UK is still in Europe. They didn't move from the continent.

Except for Ireland.