It's not actually early technology, it's been developed since the 80's. And if the underlying theories are unsound - if it doesn't even work in theory - then putting more money in won't make it magically viable.
2. It is worth mentioning that by the standards of your comment, the time between conceiving of a classical computer (Babbage) and a scalable electronic computer (ENIAC and family) was about a century.
3. While ultimately there might be a "quantum winter" in the next few years because we (I work in the field) overpromised, this would not be the first time a tech that ultimately works gets disregarded for a decade or two because of mismanaging expectations (e.g. Liquid Crystal displays or neural networks, which were both developed for many decades before being commercially viable).
EDIT: And yes, there are some startups with misleadingly general pitches.
The perceptron was developed in 1940s and only became useful in the 2000-2010 range. So 60-70 years of development time.
If we take 50 years as a baseline (faster than historic examples; but underestimating), we’d expect a quantum computer some time in the 2030s.
Is anyone here hard objecting to QC in the 2030-2040 range?
Liquid crystal displays were commercially viable 10 years before they became commercially available.
Source: my dad worked for a company that made display tubes for CRT manufacturers all over the world. He told me back in the seventies that they knew how to make TVs you could hang on the wall like a picture, but weren't making them because they were camping on a lucrative market.