I can't see a question in your post, so it'll likely be closed as off-topic. Reddit would be a better place to invite discussion, which isn't what Stack Exchange is for. I'll respond to several of your points in the meantime trying to remain as objective as possible.
Yet, on the Ethereum wikipedia page https://en.wikipedia.org/wiki/Ethereum, it says that only 13% of the total supply were mined in the initial pre-sale. Why do they say that,
There's some ambiguity here.
The 13% they mention is what was premined for the Ethereum Foundation itself.
You'll see from EtherScan that the presale of 72M ETH was split into "60M Crowdsale + 12M Other". The 12M ETH was kept by the Ethereum Foundation, which at the time was ~17% of the total. This now accounts for ~13% of the total, which is what your Wikipedia link says.
At the time, there was only 72M ETH in existence, so ~83% was sold to the community. The current supply is 99M ETH. You'll see on EtherScan that the 99-72 = 27M ETH has been mined by the community, further diluting the original holdings of the Ethereum Foundation (and those who bought at the presale).
Additionally, I get the feeling that this facet of Ethereum's roots has been "whitewashed" from the internet and within Etherem's companies, because it looks bad on Ethereum and its founders have the wealth to do it.
The Ethereum Foundation is a registered non-profit company in Switzerland. Their status as a non-profit limits what they can do with the money. (I'm sure if you Google "Stiftung Ethereum" or "Ethereum Switzerland GmbH", their formal name, you can dig up various publicly available documents that formally state how much money they have and what they do with it. Which is presumably "pay people to make Ethereum stuff better". Note also that the tax laws for Swiss non-profits became more stringent at the start of 2018, so there's likely even more information out there.)
In my opinion, Ethereum is a great product but it's not suitable as a public currency.
(Next part is speculation): I'm not convinced it was ever meant to be. Certainly nothing on the Ethereum homepage has ever claimed that as a use-case. (There's always been something about issuing your own currency through smart contracts, but nothing about ETH.)
I have never seen an article describing the potential impact of such an uneven wealth distribution within the future of currency. Imagine if 80% of all US dollars were controlled by less than 100 people
The 3 richest Americans are as wealthy as the 160 million poorest Americans put together (Forbes article). That's close enough for me. (I'm British - I'm sure a similar thing holds here.)