I'm pretty sure you are not the only person who asked that question and many have done blockchain analysis to uncover the owners of those unidentified wallets.

Imagine you own the wallet and did your best effort not to be identified with that address. You would want others to stop digging. There is this thing called privacy.   

I only believe that those holding the address are related to one of the exchangers, logically the price of bitcoin is now more valuable than when it came out into the world. When viewed from individual bitcoin transactions only spend a few digits of bitcoin.

Most happy when you have many assets in your wallet address but never hold your assets with long term, bad thing when you got problem when bitcoin and altcoin of your assets going down and never back any more to the higher price, I think better sell and buy during get moment with higher price and you have chance to buy when begin with lower price.

No one knows on who do own those wallets.Some of top wallet addresses are exchange cold or hot wallets but you can really differentiate which is a personal one but most of them
are long time dead or doesnt have any recent transaction neither those wallet are on cold storage or totally lost wallets in void.Seeing those numbers makes me drool and
i do feel stressed to think that having 5 to 6 digits amounts of bitcoin is totally lost in space. 

It is actually more than that according to some studies. It is said that around 4 million BTC is lost in total so far. Link- https://fortune.com/2017/11/25/lost-bitcoins/

It is not always good in my opinion. At some point, btc will not be existed because of the lost BTC because if the supply decreased, the volatility will be more higher than now and people will never be interested to use such a currency.

If this addresses were involved with exchanges. I think they would be known to everyone. It seems like they belong to individual person. It's not important to know who own them but what's wrong with knowing that if anyone knows? I'm just curious.

If I know you own 10 BTC here and there, would you be fine if told people around you "hey, this guy has 10 BTC here and there!". And then an hour later, you got many spam messages asking for a donation, or worse, a hitman coming to $5 wrench you.

Sir/Ma

Let me throw more light;
to me it seems as if those people holding those wallets may decides not open or initiate any transactions till their specified time which they want to operate with it. I could vividly remember my boss who brought me into blockchain and bounty said, he wanna buy BTC up 1000btc as then it was $17k which was 2017 to 2018 either and saying he could only operate on it wen it will get 50k USD per BTC.
so you see, someone would decide on a particular thing and stands on it, so in this aspect they are not dead and those wallet can not displays his name.
the wallets that can displays names could only displays the creator or the owners of the token who generates the coin from Adams so if any other person is making use of the wallet then it will not show his or her name.

I agree why would those top crypto owners want to expose their self ?
They wouldn't gain anything from it just some attention and they could even endanger their family by doing it so it is wise for them to stay hidden.
Put yourself on their place if you are one of the richest person on crypto would you tell it to the public exposing yourself and being target of the hackers or other people?

As you can see addresses nr 3 and 4 are not tagged but have very recent transactions so these are also cold wallets of some exchanges. We can assume that since there's no coinbase or bitstamp address in that group they could beloing to those companies.

I'd say that every address containing more than 10k BTC (not counting Satoshi's coins) belongs to an exchange.