Based on what I've seen when looking underneath both trucks and based what I've read and heard, like you, anecdotally.
While the frame on the Tundra is one area I'd like to see beefed up (fully boxed), everything else about the Tundra seems overbuilt (transmission, transfer case, the 2-piece drive shaft, rear axle, brakes ect.) compared to other 1/2 tons.
I don't have a grudge against the F-150, or Ford in general, but rather I don't think it lives up to all the hype and brand loyalty that revolves around it. I hear people claim all the time that F-150's sales #'s (arguably the best in the segment) are proof positive that the truck is the best within its category. There are way more Ford Fusion's and Chevy Malibu's on the road than there are BMW 3 series....does that mean the BMW is an inferior car?
I'm not arguing that the F-150's are analogous to Malibu's and Fusion's while the Tundra is analogous to a BMW sedan; rather I'm saying the logic of that popular argument is faulty. I think Ford makes their F-150's good enough; I think other brands and categories of trucks are over-engineered to better handle long-term abuse....that's just my opinion.
Funny thing... the F150 is rated to tow more, and haul more. It's.5 sec faster 0-60 unloaded and many seconds faster when pulling a 10k trailer...and to top it off it has a shorter stopping distance. Best part is it does all of that while weighing less and using less fuel.
The Tundra is an antiquated design built on a decade old platform. Is it in any a bad design or underpreforming design, absolutely not. Has Ford used stronger materials and more advanced engineering to build a better performing truck, absolutely.
So do tell... how do you justify your claim that the Tundra is "overbuilt." Toyotas engineers and attorneys don't seem to worship at the same alter of Toyota ruggedness that you do.