There's an alternative that exists already: ACIS-resistant protocols that require a large amount of RAM to mine. It still needs processing power, but you can't really avoid that if you don't want the content of the RAM to be stored on disk.
You are correct Loyce, the point I was trying to make is that no matter what protocol you use in order to achieve any sort of decentralization is always going to end up in the same way, ACIS-resistant protocols, a recent example of that is Chia coin and its protocol which is based on both proof of space and time, all you need is a hard drive to store the plots, and a processor to make those plots did not take long for someone to figure out a way of writing that space with RAM in a faster and cheaper way.
The argument people had of how that protocol was more decentralized than BTC's POW is that fact that people had better access to HDDs than to ASICs, it took only a few months for that theory to go out the window, videos of large farms with thousands of HDDs were floating around, in just a few months every average Joe with a few 10TBs HDDs was not able to make any profit.
It doesn't matter what protocol you use, the end result is going to be pretty much the same, people that know how to make money will always find ways to make more money, even when you give the average Joe a chance to make money he will miss it, so thinking that ASIC miners are the problem and by using something else absolute decentralization is going to be achieved is daydreaming.