The power of the Ring was such that nobody, not even Elrond, stood a chance of intentionally acting to destroy it. Elrond couldn't have pushed Isildur if he tried. Frodo and Gollum only managed to get the ring into the lava because they were fighting to keep it for themselves and went over the edge accidentally.
I'm sure that would have looked great to all the gathered men who were still alive.
"oh yeah, the elves showed up and one of them went up to the crack of doom with Isildur after his father died, and the elf came back alone and wouldn't tell us what happened inside. Something's fucky. We better prepare for an attack from the elves."
Whether anyone actually threw hands immediately or not, men and elves would have a far shittier relationship after that.
The question is, did more suffering occur because Elrond didnt do this? We can't know.
...and Gandalf the Grey spent 3 weeks drinking and smoking and setting off fireworks with the Hobbits, remembering his old friend Bilbo who died some years earlier after an average hobbit lifespan with his nephew Frodo...
Gandalf wouldn't even still be there, since he was only there to aid in the fight against Sauron. He'd have gone off to Valinor shortly after Sauron's defeat, together with the rest of the elves. And there'd be no Aragorn to be a good pal and extend the good lifespans of the realms of Men, so Gondor would never get a new king and the realms of Men would likely fall to evil a bit into the third age.
Would goblins/orcs still have endured without the lingering evil of Sauron?
They weren't naturally occurring (yes they bred but they were made to be a breeding army for evil and I'm pretty sure Tolkien alluded them to dying out quickly after the ring was destroyed) in Tolkien's lore I'm pretty sure and were interchangable terms for the same species in his lore even though they're different in others.
You know, there's actually another trilogy even better than Lord of the Rings that was never written because this exact scenario played out. You would have loved it, but the guy who killed the other guy really did everyone a solid.
He didn’t live happily ever after anyhow so nothing was lost. Also I think he kinda spar on the lives of everyone who died that day by keeping the ring sooooo too bad.