Your first statement is wrong.
Remember old cheap "dumb" phones?
I had a friend, who literally had it washed in the washing machine by accident. He let it dry for 2 days, before turning it on, again.
Still worked.
Try this with a "smart" phone.
Yet, the "smart" phone is highly "optimised", much more expensive, luxurious, etc.
Similar thing with laptops.
Back then, bulky & heavy laptops could fall to the ground & it was fine for a long time.
Now, with all those so-called "Ultrabooks" etc., you have to watch out to not break it or it's screen during normal usage, outside.
These are just two examples out of many, where "cheaper", heavier & bulkier means, it actually lasts way longer, than a highly "optimised" edition of the same type of product. :)