That is most definitely not the case for most start up companies I work with. Not have a CEO day one who runs the company is usually a sign that you have not started a company before.
Most C-Level employment decisions are made by the board on behalf of the shareholders. Many new companies do not have a BOD yet, so the shareholders will have 'direct' representation. Extremely early stage companies will have all of their shares split between the two founders.
The mere presence of a "CEO" title doesn't grant one founder domain over the other(s), and it shouldn't, but this helps explain the frequency of founder drama.
The mere presence of a "CEO" title doesn't grant one founder domain over the other(s), and it shouldn't, but this helps explain the frequency of founder drama.