Did you miss the announcement? They released a trailer, which revealed the year it's releasing. 2025. It was even leaked a few hours beforehand, which was quite a big deal in itself.
And it showed a beautiful new/upgraded engine, introduced some new characters, and revealed absolutely nothing about gameplay, yet this did not stop seemingly tens of thousands of people from pulling whatever their idea of a neat feature is out of their ass and connecting it in the least substantial way possible to some random part of the trailer.
In fairness the scale of these games has increased sharply, and they have released other equally big titles in between (namely RDR). I'd rather wait until they're satisfied with the product than play something unfinished.
Look at it from console generations. The Xbox 360/PS3 generation got two GTAs (GTA IV even got two add-ons), RDR, and if you want to count it L.A. Noire. The PS4/Xbox One generation got RDR 2 and a rerelease of GTA V. I doubt it's about scale, they just wanted to milk GTA Online and didn't care about anything else.
What GTA5 came out in 2022? 🤨 AFAIK, it only had 2 separate releases; the first on consoles, then on PC a year later. Like has been the case with every GTA since 3.