David Amador16 years passed between GTA1 and GTA5 release date. And since GTA5 released 10 years have now passed. Games are more complicated than ever to make, added resolution to assets, realism mechanics, online etc add a real time cost to all.
ima@djlink Doesn't really make sense to only look at one series from a game company, that also develops other games, in isolation. RDR2 came 5 years after GTA V.
Also, GTA V Online has been massively profitable, with loads of content being released regularly, so it wouldn't make sense to focus on a successor too soon, so RDR 2 was definitely the most sensible option for them.
III, VC and SA are basically the same games, the others are massive upgrades technologically, so obviously a bigger gap.