Not all leadership roles are created equally.
A CTO role at one company can be very different from another company. (or any leadership/management role)
The things you focus on with a technical team of 10 people are very different than 50+ people.
At ten people, you might be very hands-on. At 50+, you can still be technical, but you'll need to be better equipped to work with an exec team/board, strategy and processes. (side note: A lot of startup CTOs find themselves struggling in this position)
I find people go wrong because they don't "grow with the company" as the company moves into different phases of its growth lifecycle or when they take a similar role at a new company without considering the current growth stage or culture.
They still have the same title but not the skills to do the role as time passes.
I mention this because, when reflected upon, it can be to your advantage.
Firstly when taking a new role at a new company, you are more likely to find a better fit if you know the types of companies (team size, revenue, culture, etc.) you can add the most value in and decline the ones that don't match.
Secondly, if you are in a current role you want to keep, and the company is growing beneath you, you can start to identify mentors and resources you need to match your growth to the new demands of the role.
Your main risk here is unknown unknowns, so you're only in real trouble here if you don't know you need to level yourself up and that it's ok to be in this position. (as long as you identify it early)
Thirdly, you also might conclude that even though the company is growing and the demands it makes of you changes, you prefer to work at an earlier company lifecycle and make a graceful exit instead. (nothing wrong with this)
Spending time clarifying this has greatly benefited my career, and I encourage you to think about this.