GTA VI has been in the works for years and years, it's probably in development hell.
They are 7 years "overdue" from the previous release, but that means nothing by itself.
The last GTA game took the longest and would have seemed past due before release, but look at the level of depth it had. It's still the top game over a decade later.
Most importantly they never give a due date too early for this exact reason.
My point was, it takes a longer time each time and without seeing the level of gameplay you don't know whether it's mismanaged or simply an extensive game being developed.
You also don't know the percentage of their resources they put towards it. I'm sure maintaining and developing GTA Online took at least some resources.
Either way, I'm not going to shit on the one company that actually knows how to make full games.
Looking at you CD PROJEKT RED... (cyberpunk was a joke right?)
Also, rockstar did make an effort to cut back on crunch after red dead 2, so the result is longer timelines. R* going back to crunch probably feels like backsliding to employees.