Yes, this is entirely true as well. Though US companies face this effect as well. But as a result EU companies get practically no competitive advantage compared to an American company when they want to operate in other EU countries, and if the EU wants to exist this imbalance of power need to be addressed or it will keep snowballing.
A successful french startup means a loss of jobs and wealth to other countries. DACH customers will prefer working with DACH companies, French customers will prefer working with French startups.
If you dont work in english speaking environment (IT) moving countries within EU is practically impossible for people working normal jobs.