can't address all the 4Runners in the world, but my 1988 has over 300K, and is still running strong.
The items I have mainly replaced recently, were some front end components, radiator, O2 Sensor, and some electrical things. Replacing the combination switch in the steering column next week.
Other than that, normal maintenance has been enough. You have to repack the hubs, do brake changes and that sort of thing on all vehicles.
