Is abandoning my PhD degree better for my career path?

Your argument for abandoning your PhD hinges on a few false premises.

P1) You will wear the mark of your PhD for your whole life.

That is not true. A PhD is, in principle, a degree given to someone capable of independent research. Whilst you do your PhD you may be associated with your supervisors. That's because you're a minnow in the sea and it is the easiest way for someone to know whether you are worth talking to (sorry about that). After your PhD, people will rarely if ever ask that. I say that as a postdoc.

P2) You will exchange your dignity for money if you renew your contract. WHAT? That's something internal to you, an external observer is unlikely to see it that way.

Moreover, if you do not intend to do a postdoc, none of these points you made will apply to industry people. They will just see that you have a PhD and they will think that's worth something.

I strongly argue that a mediocre Ph.D. is better than no Ph.D.

The standard path to bootstrapping yourself up after a mediocre Ph.D. is a sequence of rising postdocs. If you're really good, then when you move to a new institution with a postdoc, you should be able to do some nice work and build your reputation. After a year or two of that, you can try to move to a better institution with better resources and more interesting projects and do yet stronger work, etc. Doing two or three postdocs is not unusual, and is one standard path for improving one's lot after finishing a Ph.D. Moreover, even if your institution and/or advisor is known for their mediocrity, that may not count against you: "They didn't do something very interesting, but how could they under Prof. Boring? It looks like they did well with the topic they had to work on, though."

If you are interested in being a high-profile researcher in industry or other non-university research institutions, the path looks much the same (in fact, some positions in industry and elsewhere are explicitly set up as postdocs). Once you move to "permanent" positions, however, you will likely want to take a longer period between moves, so that you aren't perceived as being unable to stick with a job. For that reason, term-limited positions like postdocs are likely to be better for rapid mobility.

For many research positions, however, you will simply be disqualified (either explicitly or de facto) if you do not have a Ph.D. A Ph.D. is a minimal bar that shows you are capable of scientific work of some sort, even if mediocre, and if you have dropped out of a program, many people will assume you found you could not do this. You might be able to get around this by going through the world or tech start-ups, DIY engineering, or other non-standard routes, but this is much harder and the (scientific) success stories you hear about from these are very rare indeed---these worlds tend to make impact in other ways.

In short: a Ph.D. is a much straighter path to scientific prominence, and there are good approaches to help overcome mediocrity in your origins.

If you dislike it as much as you imply and you're actually 2-3 years away, then by all means find something better to do with those years. But you say that you're very close, so I'll assume 6 months in my answer.

If I had to do it all over again, I would have not gotten my PhD; it was too much of my life that could have been better spent. However I have absolutely no regrets about the final 6 months, as difficult as they were. I recommend that you finish. Tech bubbles come and go, but potential employers and investors will always pay more attention to you if you have that particular set of initials. You will also gain personal experience in finishing something big.

Finally, if you're concerned that your project will yield valuable IP that the university or your former advisers will lay claim to if you complete it as a student, talk to a lawyer. Otherwise, as others have said, the "tribe" reputation stuff is nonsense.