This is a totally personal question.
It depends more on what you want and can do.
You may learn to draw and make 3D models, but doing it well will take time, it's not something you learn from one week to the next.
It will always be better to have a person who is specialized to try to patch the holes yourself.
A person who dedicates himself to modeling in 3D every day will have better results in less time than what you can do, because in addition to modeling, you will have to spend time programming, designing, etc.
It is not difficult to find someone to help you for a few days or for a short game, but it is very different, if it will be a long and complex project. Most people get bored or have to spend time on other tasks.
Ideally, you should have specialized people, but depending on your project and budget, this may be impossible.
In those situations, it's time to be plan B, the contingency, do everything yourself.
I say this based on my experience, maybe you have a natural talent and could generate excellent 3D or 2D models, that's why this type of answer changes from person to person.