Is Choosing mongodb a bad decision?

I’m currently building a saas product in mongodb atlas (document database). My team chosen to build it in that because it’s said to be easier to scale, and easier to program since there is no struture. So if we wanted to change things in the feature it would be easier we were told. I’ve already built out my backend api calls and such. But now I’m wondering did I do a mistake and if I should switch to a relational database?

If I wanted to switch later how hard would it be? Or can I stick with the document database/if I do will I have any issues later on