The only short-term solution is more regulation and more EU-centralized solutions, but of course this is only ok until the next chat-control drama.
Long term, in practice we need single European stock market and a way to provide funding to European companies from any member state, so to be competitive globally without being constantly restricted by every member state’s bureaucracy.
New York alone has 2 stock exchanges. I don’t think that companies being listed in London, Paris and Frankfurt (they generally are listed on several anyway) is the actual issue.
Especially these days the stock market is the very final stage anyway, most funding for growing tech companies is private funds, vc etc.
When Trump was invading Denmark, a huge % of Danes would've given a shit about sovereignty from the US. And that's the moment to pounce.