> Toyota LandCruiser for 20 years

Respectfully I specifically wrote "new." 20 year old SUVs predate the issues of new vehicles.

> my 2016 4runner

Even a 2016 vehicle predates what I'm pointing out. A 2016 4runner likely has a 270hp naturally aspirated V6 with modest power and a relatively basic 5 speed auto transmission. A 2025 4runner is a turbo charged 4 cylinder making nearly 2hp/cu in. and an 8 speed transmission. The former is much simpler and thus economic to maintain and repair compared to the latter.

ICE vehicle drivetrains have changed radically in only the last few years. They're almost universally using forced induction, integrated into unserviceable castings, to attain far higher volumetric efficiency, equivalent to high performance engines of not long ago. Gone are the 4-5 speed transmissions and transaxles: 8-10+ speed is the norm, and the complexity follows here as well. They are absolutely intolerant of neglect and abuse. Repairs are complex and likely to fail: manufacturers have taken to replacing major assemblies in leu of attempting repairs as they would have in the past. Part of that is due to the unserviceable nature of these components. Another part is the lack of dealer talent to deal with their own products. Another part is that the manufacturing lifecycle of major assemblies is now extremely short: only a couple years, whereas 10+ years was normal for common platforms as recently as the the 2010s.

What this means is: when these new products are no longer supported by manufacturers, who will drop their supply obligations rapidly as they legally can due to short lifecycles, parts will be fabulously expensive and difficult to obtain and the skills and tools necessary to repair them will be rarified and also expensive. Post-warranty ICE vehicles will be uneconomic, full stop.