Does a Land Cruiser last 25 years in dry areas of Australia? Yes
Does a Land Cruiser last 25 years in the wetter UK? Not as well - the body tends to rust out well before the motor gives up.
It depends on where you're looking, and what engine. I know of petrols with 400,000km on them, I know of diesels with 650,000km on them (I've driven both of them - the petrol was a Troopy, the diesel a HDJ80) in Australia. The Troopy had rust in the roof gutters, the bulk head (you got a wet foot driving it in the rain, in fact all the work ones did that and at the time they were 25 years old - my own one which was an inland car, and a fraction of the KM's didn't give me a wet foot) The 80 series is an inland car, from an area with 800mm annual rainfall, so has very little rust in comparison.
Ultimately, the Prado/Colorado/GX is based on a HiLux platform more than the Land Cruiser platform - suspension is in common with the Hilux rather than the 'Cruiser - so there are some compromises to be made there. I regularly see VZJ95's Prado's for sale with 400,000km+ on them, and even GRJ120s seem to be good to those sort of KM's. Not sure on the V8s, but they seem to do big k's in the Cruisers here as well, so the engine is good, just not sure on the body and chassis. Bearing in mind, these cars with these k's on them are often Australian country cars... a trip to the supermarket in some
rural areas is a 250km round trip, and that's where they pick up those k's.