Right now I'm at the point of giving up again because it's so damn hard to find customers here. In my opinion, for deep tech startups the problem is not primarily access to capital but access to customers, as the corporate culture is extremely hostile towards startups. Large corporations are very risk-averse and most of them won't ever consider buying a product from an unproven startup. The ones that want to work with startups often have started their own incubators where they try out ideas by hiring teams and building startups that they fully control (50 % shares belong to the parent company from the beginning).
Also, from my experience getting seed funding becomes harder the more experienced you are here: If you just finished university it's easy to get a so-called EXIST grant, which will pay a little more than 100.000 € to fund a team of three people for a year. That's how most (or at least many) of the successful startups get funded here. The thing is, if you have been working for 5 years or more you will be ineligible for that program, and your options for getting seed money are very restricted. This is weird as people with industry experience usually have a much better chance at building something relevant and successful than a recent university graduate with no business experience. They have a much harder time finding money though.
There are counterexamples and very successful deep tech startups of course, I just think we could have many more of those if we had a system that actually encouraged and helped people to build these companies.
I can understand that many people decide against it, especially when you're a good technician / engineer you can earn much more in industry and there's very little to gain by leaving your position.