I mean, based on Goro's movies, it's clear he just isn't as talented as a filmmaker as his father. Besides, Suzuki Toshio is the Tim Cook of Ghibli.

I have no doubt that Goro wanted to be his father's successor (why would he have made multiple films under the Ghibli umbrella), but his father clearly recognizes that Ghibli has a potentially larger future than becoming a lesser studio under his son.