Earlier quoted context omitted.
What I wrote is in no way contradictory to your experience. Great tech MUST be sold, once you have the proof of concept you must get someone great at marketing on board to help you sell it. There are plenty of great marketers who can help you with this (for a price...). My only point is as a great technical person you start with getting it working before trying to sell it. Once it is working great marketing people wi…
I believe what you say is directly contradictory. I'm suggesting you definitely not get it working before you try to sell it. For most product ideas, the key question isn't, "Is this possible to build?" It's, "Will enough people buy it to make a sustainable business?" That is to say, the greater risk of failure comes from lack of demand, not lack of technical competence. The greater risk should generally be addressed…
As a technical person you are better at getting it working so spending a couple weeks getting a working prototype is worth the effort, it might be ugly but it builds trust that it can work. If the idea is radical your potential investors/customers won't believe it is possible.
The real problem is until you have enough paying customers to pay everybody you are living on borrowed money. How you best borrow the money is the only question, and the answer if different for every situation. Some ideas are so obvious when seen that you can get millions from investors. Some ideas will get the "that ain't possible" reaction until you show them the finished product when they will beg you to take their money. Some ideas look cool but nobody is willing to actually pay for them. Some ideas are cool and will generate sales - but never enough to pay for all the people required to make the product. You have to figure out where you are.