I don't know the exact percentage, but most of BTC is owned by a few.
So logically, BTC can never become a store of wealth for the masses.
BUT if BTC cannot serve as storage of wealth for all and neither as day to day currency due to very slow and increasingly expensive transfers, what role will BTC play in the future?
I honestly think that it will become a billionaire's toy in the future and coins like XLM which offer incredibly fast and inexpensive transfers, will play the major role in the financial day to day transactions.
So I believe that the people who have just started to invest in crypto should consider these other coins and forget about bitcoin.
If the world will accept crypto as currency, it won't be BTC.
First of all most people do not even have savings to begin with so they have nothing to store in bitcoin, if things were different then we could see bitcoin serving as a store of value for them, the same happens with gold by the way, do you think that people actually are holding gold? Except for those that have a few pieces of jewelry made of gold the rest of the population is not holding any so that is not something that worries me at all.
The real challenge come from everyday use, the fees are very expensive and as long as that is the case then making small transactions is not an option, you can do several things to lower that cost but even those measures are not enough so we will have to see if the lightning network which was the proposed solution to this problem actually works as advertised, if it does then bitcoin will also become the coin that we will use in our everyday transactions.