While I do not discount the fact that oligopolies can be just fine. I also observe that healthier competition should produce more real innovation. I don't pretend that innovation does not exist and you bring up a good example. The market for personal technology has been evolving (if you don't count the iphone) and that's a good thing. But I would argue that this is largely because differet firms are beginning to dip their hands into the same pot, not becuase of true competition. but because fo the nature of the devices we carry. We have phones with distinct operating systems which access the internet and drive a healthy app market. Suddenly it's not just apple and miscrosoft in the personal tech business. It's apple and microsoft and google and all the phone companies competing, and all of them competing with ISPs (google fiber, verizon hotspots). Also, its important to point out that while many American firms are innovating. Innovation cannot be the sole driver of an economy. America is relying very heavily on innovation and skilled labor to fuel its economy and these two areas simply don't have the volume needed to fuel the largest economy in the world.
As far as more optimal things go, the critics of my stance have a valid point. Alternatives are limited. But that does not mean they do not exist and it does not mean that they are even vastly different. I think that a model based on capitalism would be best for most countries including the US. However I also think that there should be more intervention in markets with regards to how they operate. But then that's where you need to be careful, while intervention can prevent crises it is suboptimal on the smaller scale environments. I think that the united states needs to seriously consider both more protectionist policies and regulation in markets where competition has stagnated. One of the reasons it is so difficult to do this is that market tend to be as different as the countries that there are in. What works for one area and good might not work for another so there's no sweeping answer to all the questions. Rather, a thousand little ones. Personally, I think we need to start with heavy industry. While it's true it is difficult for us to complete with the cheap unskilled labor of many countries I think markets exist both domestically and abroad for goods in different prices ranges. The main implication of what I'm saying here, after you muddle through the inbetween, is that countries who do this would see the price of goods increase and level of employment increase. While a dollar would not stretch as far domestically it should not lose value internationally, and as it stands now it is important for America to keep the dollar trustworthy as a denomination to own debt in.