The cool thing about thrash was that it was the most extreme form of metal around. That stopped being true around 1987. Obsolete as playing Intellivision on a black and white tv.
But as a whole, thrash is not so much dead as it is mixed with other styles of melody. I really like this. Bands should put whatever musical influences into their metal that they want, so long as it makes it cooler. They shouldn't limit their metal's originality so that it fits a particular subgenre. That's weak sauce.
I'm easily bored by bands that are just straight-up thrash or straight-up death metal.