Spending of those dollar amounts in the US started decades earlier, and coincided with massive amount of military spending e.g. on radio and signals tech going back to WW2.
Once there now is one hub, you should expect trying to create a competitor to be vastly more expensive because you have to counter the draw of SV.
E.g. every effort to bolster the tech scene in London has sort-of worked, except a portion of the most promising companies then leave for Silicon Valley. This is repeated all over Europe.
Similarly, within the UK, I worked for a VC for whom part of the goal was to bolster investment in the regions, and we faced the constant struggle that because founders (rightly) assumed that most UK VC's preferred companies in London, a lot of the most promising companies moved to London before we got to them.
For that matter, I live in London because of this situation. I moved to London with my startup at the time because after getting funding in Oslo our VCs advised us there just wasn't enough capital for tech startups in Norway at the time, and so we moved to London for better funding opportunities.
Pouring funding in lifts all of these ecosystems, but it also hastens the departure of the ones who get the most benefit unless you do so well that you remove that incentive. Or attach strings to your funding. Fixing that will require you to provide so much capital that more startups start seeing staying in Europe as making their funding situation easier.
That means plugging the vast gap in later-stage VC funding between Silicon Valley and Europe, not just some R&D grants here and there.
That's not to say I think the European R&D funding efforts have been good enough, but it'll take many times as much funding, and a lot of extra effort, before you should even begin to hope to get the same outcome.
