Hi Karma and welcome to the site.
You're entitled to your opinion and for the record, not "everyone" here thinks RDR2 is the "greatest" ever nor without faults. ......but you are on a fan site so yeah, I would expect you might run into folks who like the game.
There are quite a few of us who have been playing (some off and on) since the beta on console. The content that there is now is much more than what we all started with but I do see people's desire for more. I wish it too. The thing is, content is cumulative in this game like it was and is in GTAO. Obviously, GTAO has had a lot longer to accumulate more of it. .....but RDO will become more robust as time goes by. I suspect the trend for content drops will continue for this year as well and R* has already said they have a lot more planned.
Either the PC community in RDO is way different than console or GTAO PC is a really mellow place to be because it's the exact opposite for me on PS4. That said, RDO has it share of griefers but they are way easier to avoid than in GTAO IME. .....although you guys have those problems with modders and hackers we really don't.
You haven't missed much in that time as there hasn't been any significant content added between then and now. Nothing wrong with shelving a game for awhile that you get bored with in between updates or even leaving it all together if it's not your cup of tea. Nothing weird about it. RDO simply isn't some people's cup of tea and that's fine.