If there's a company that will create powerful smart phones that can be dedicated to mine, I wouldn't buy it.
Parts of smart phones are tiny and the heat can cause it to break and lose on it's original status. In electronics, the tinier the part is the more vulnerable it is.
That's right , but we can never know how the technology might evolve. I'm sure will be seeing companies trying to provide this solutions and offer crypto mining Chips adapted to a mobile hardware. Why wouldn't you buy a powerful smartphone that is also featuring mining?
Yes technology is evolving and there will be things that will come which we didn't expect to upgrade.
It can be possible in the future that you can mine with powerful smartphones but still considering it's size and compatibility, I don't really think it will be good for mining.