Ages and Longevity

First let me say, that it has been about twenty years since I played that first and most popular FRPG. In know a lot has changed, but not everything. I have a bone to pick with the age of the characters. In my games, elves, dwarves, humans, halflings, etc. all have about the same lifespan. That other game has elves living over a thousand years and dwarves going on for centuries. The problem is - They don’t give them any credit for it.
Here’s what I mean: A human is ready to go adventuring at age 18-25. I forget what it is for elves, but it’s about 300 I think. Within five to ten years of adventuring (assuming survival), a character can get to level 10+ depending on the GM. OK - So let’s assume that the human adventurer calls it quits as he/she approaches middle age. The elf is just getting started. He’s got hundreds of years to go before he hits middle age. But look at your books. The average elf is about as experienced as your average human. All they get for hundreds of years of training is +1 with bows / +1 with swords. Oh, and some extra languages. Same with dwarves. A one hundred year old dwarf is considered ... wait for it ... only as good as some 21 year old human. What? The dwarves aren’t training their militias? Fifty years of dwarven drill sergeants and the guys is level 1? I don’t get it. Oh, it’s game balance. call the PC police, it’s game balance again.
What about the cultural impact of eternal life? If I were going to live for 1400 years, I would be a pacifist. Why would you ever risk another 1,000 years of life over a battle? Don’t worry if the orcs enslave your entire people, you’re going to outlive them, or at least outlive this current empire. After they are all dead from civil wars, you can go back to your gardens. And if all the oak trees are dead, grow some more. After all, oak trees would be like corn to a 1400 old elf. OK, maybe like a rose bush. (For those of you who don’t know, you cut rose bushes down to next to nothing every year. It’s the only way to get them to really grow.)
What about retirement? Do they amass huge sums of money so they can live in retirement for 400 years? OK, the dwarves would. What about the really active ones? I know there are good GMs out there who have monumentally powerful elven wizards and druids. After 1,000 years of learning and experimenting, you should be beyond incredible.
So how do I balance the game? Well, not by being a slave to Tolkien. Everybody lives the same 75-100 years (depending on the state of their health care abilities, both mundane and magical). I mean, I like Tolkien too, but my world isn’t Middle Earth.
I can’t help but think about the elven peasant. Here is a guy who farms a plot of land for 800+ years. I mean, really, 800+ years on the same plot of land. The assumption from that old style game is that after being there for, let’s just say, 500 years, he’s a level 1 guy. If he were really going to farm that piece of land for centuries, wouldn’t he go to night school for druidic magic? I mean, ten years of night school should triple his crops for the next 1000 years. Even if he didn’t, he’d probably have named every earth worm who lived on his land or at least know its genealogy.
OK, I’ve gone on long enough, but I really am interested -What am I missing? Did they fix the game so much that any of this actually makes sense now?