The EU cloud may win only by shifting the paradigm.
Take Microsoft Office as an example.
For many years, Open Source and businesses tried to make a Microsoft Office competitor by mimicking Microsoft Office. Naturally, all clones were worse than the original and they either failed or stuck in their small niche... until Google changed the paradigm and rolled out Google Docs that had a unique feature of online collaboration.
Then was the turn of Microsoft to mimic collaboration features of Google Docs in Microsoft Office and be worse at it almost by definition.
Another example is S3.
For years, businesses tried to have POSIX-capable filesystems seamlessly scale in size and in availability. It took Amazon to roll out a simpler alternative that, by having a smaller set of features, enables so much sought properties of distributed file systems in an efficient and commercially viable way.
Back to EU clouds.
Scaleway tried replicating AWS, but they are and will always be a worse AWS than AWS itself. That Microsoft and Google could force their way through is more of a marketing win and just proves my point.