Grand Thief Auto (GTA) is a series that has long been deeply imprinted in the childhood of many young people in Vietnam as well as around the world.
GTA began its development path in 1997, thanks to DMA Design (the predecessor of Rockstar North).
Firstly, Rockstar currently has many other large projects that need investment.
That means the studio has almost mobilized all of their resources to develop for RDR2.
The second reason, GTA 5 is still bringing Rockstar a lot of revenue.
This raises the question, why does Rockstar have to spend money and manpower to develop a new version of GTA when it is still making them a lot of money.
In short, Rockstar has a good reason for not investing in developing GTA 6 in recent years.