I see no problem investing in ETH to be honest, ETH is still in the lead, IMO. As long as you will use it, I don't know why you would be worried in the first place because it will not affect us as users.
Same here, ETH market is pretty solid and it has liquidity. We don't need to be seriously attached to a cryptocurrency so whether it is centralized or not, as long as it will give us profit, why not take the opportunity to earn from it. Meaning, if we find the ETH market profitable, why not take advantage of it. We are just buying it to sell in higher price anyway.