Sovereignty is mostly just a protectionist racket. European firms struggle to compete with dominant US platforms, framing industrial policy as "sovereignty" rather than protectionism just sounds more strategic and security-oriented. I've seen US platforms bend over backwards to meet the requirements and they still choose their preferred winner. Predictably the goalposts keep moving.
Sure it vibes very well with protectionists but the sovereignty angle is real. The USA is no longer a reliable partner.
(And just before someone mistakes my comment as having any stance on W Social, I do not)