Endless changes without starting

There is such a phase in any startup when you want to endlessly improve and redo everything, dismissing previous developments. So, we ran into such a problem with one of our clients. It was an interesting and high-tech startup at first glance. But the problem was that the customer endlessly tried to improve everything without launching the MVP. As a result, more than a year was spent on development and a large number of efforts and funds were spent, which led to the termination of funding and our negative attitude towards the project.