Dynamic Action & Forms was released at Summer'20 Release , which was a beta version. But now in Winter'21 Release , they are generally Available for custom objects and it's still beta for standard objects. Dynamic Forms and Actions break down page layout into individual field components. Each field is treated as a component. We can make changes in individual fields. There is no need to go to page layout for customizing and removing the fields, it all can be done from Builder itself.