Furthermore, you don't need to be US based to be bought by a US company. A product like this probably will need a US presence at some point, since it sounds quite sales/evang heavy. But again, that doesn't mean you need to start in the US.
I think you might be viewing the world through fairly rose tinted glasses. I suppose I could meet a "valuable introducer middleman" while I'm in the park, but given SF it's probably more likely the stranger I just met in the park wants to tell me about the forthcoming alien invasion.
To use an analogy: if you want to be the film business, Hollywood is by far the most popular place to be. But that doesn't mean that being in Hollywood makes it any easier: there are more connections and more opportunities, but there's also far more people trying to use them. To that end, many successful people and companies in film are based outside of Hollywood. The Bay is the same: it's the place to be for tech. It's not the only place, and while there are advantages to being based there, there are also disadvantages.
https://www.cbinsights.com/blog/tech-acquisition-rankings-ci...
Numbers, please? It's not rose tinted, for the time being it's still a massacre.
Being in the right part of the US, you can meet all three - future employees, investors, the decision makers in charge of acquisitions, valuable introducer middlemen, while you're at the park or chatting with people at meetups or anywhere. Amazingly, you can meet them just like any other normal people at any stage.
You may aim to strike the "best of both" by staying in EU. Very unlikely. The extremes wind up being far easier and more enjoyable than trying to balance something in the middle.