It is not easy to be an expansion team in any sport. You have to garner a market, attract fans, potentially build a stadium and training complex. And on top of all these extra-curricular activities that most other teams do not have to contend with, you also then need to build a team and management that can compete in professional sport. It requires finance, expertise, time, patience, and a whole lot of resilience.
The 2020 Major League Soccer season features two expansion teams, Nashville SC and Inter Miami CF. Both have encountered problems throughout their preparations for their time in MLS, but, eventually, they made it to the big time.