This should be one of those things that should be an quick EU win. Running Let's Encrypt is $3-4mill a year, the EU probably uses that on pencils.
The EU could easily bootstrap a Let's Encrypt competitor if it truly cared about removing dependencies on US based entities.
Do you really think the EU wants to sign up for PR that’s essentially “the US is being too mean to Russia” right now?
Yes, but EU would have to convince Google and Apple to get a new root certificate to browsers.