Ask HN: Take founding-CTO job offer with no equity?

tl;dr: I am asked to take the role as CTO in a to-be-found company without equity in Germany. Shall I do it? Longer story: A year ago, a friend of mine and I started wandering around in Germany to get funding for a startup. Fast forward today, we figured out we are not the "classical founders" a startup would need (no/low salary, big risk etc.). Nevertheless we were able to get an interesting offer anyway: to found a subsidiary of an existing company to cannibalize their own business. He would serve as CEO and I would serve as CTO, including all rights one would have as Managing Directors but without equity. The investor would sit on the advisory board and owns 100% of the company. In exchange, we would get a very high salary (way higher than market standard) from day 1 incl. bonus agreements. This would be also true for all of our employees. We would get all decision making power, an external office just to be completely separated from the parent company. What would you do? Do you have additional advice? Some more detailed background information: I currently have a very good job/salary at $BigCo in Germany, so no pressure on that side. My dream was always to own a company which I can influence in a way impossible at $BigCo. I like leading people, strategical thinking and working together with my own team. I know in this case I wouldn't own the company technically speaking, but I nevertheless would be able to create a meaningful working culture. I'm mid 20s, no kids, no real estate and "only" bound to my SO. My biggest fear is to get dropped out of business by the owner after $X years/months when the company makes well because of the high salary (why should he pay $high to me when he can pay $less to somebody else in the future?). I inerhited the need for social and job safety from my parents and therefore I'm naturally motivated by job safety and a high salary (to buy real estate ASAP). Thank you!