Then good news! For everyone who can't decide to buy Bitcoin currently because "it's too high", you should simply wait for the DIP.

This is normal.In a bull market,most of the traders decide to HODL rather than selling their coins.
However,on the long term,the market liquidity going down is a sign that the prices might go down as well,due to the lack of a growing demand,which supports the price growth.
I don't know how accurate is this data and can we trust it,since most cryptocurrency exchange platforms are faking their trading volume in the last few years.Perhaps the exchanges are erasing their fake trading volume.

Big investors are likely buying on OTC and some withdrawing from exchanges. Everyone is holding while prices go up.

The halving effect is now also felt when few BTC goes into the exchanges. Less BTC while the demand still remains high made the prices go up but don't you think it's because Paypal had bought the virgin BTC from miners?

Good. It probably means that holders probably has stopped attempting to trade, and just withdraw their funds on their(hopefully) non-custodial wallets. My guess that these are probably old bitcoiners though, as the numbers on Google trends haven't really gone that much up yet compared to December 2017 levels.

Maybe, Looks like More institutional investor looking for other alternative investment option and the one of them is Bitcoin, As we know this Pandemic was have an significant Impact on crypto Market especially Bitcoin and in the stock there is a negative trend as far as i know. It was good news I suppose especially for Crypto community, I just hope this trend will becoming an good start for the next year market trend too.

Bitcoin is getting more scarce and expensive, liquidity on regular exchanges has been low for quite long time. Probably there will be time when price for 1 satoshi will be $20k

Yes, it may be dropping but this is what we wanted right? That everyone will going to have bitcoins in their digital wallet. I disagree that only whales could do it to leaving exchanges that drop the bitcoin liquidity. There are actually many who are new to bitcoin holders as paypal brought bitcoin to its users more easily using their platform. So, it is not the whales are doing it instead it is the people that bought bitcoin even at the current market. Whales are smart and they do not buy bitcoin at higher market price so this is not their doings for sure.

It should no surprise that liquidity on crypto exchanges keeps plummeting. The number of individual hodlers is growing, the number of institutional investors willing to acquire bitcoin is growing, the number of sagacious institutional investors, who have already bought bitcoin as a reserve asset, has significantly increased too. These all are strong hands, which means they are going to keep their bitcoins as long as they see fit, probably even decades or so. Weak hands, on the other hand, have already cashed out right after Bitcoin has reached 14000$. Naturally, they are not eager to buy "expensive" bitcoin after an unexpected price surge and started trading shitcoins instead. This is good news for bitcoin, the situation indicates that the growth potential of bitcoin is practically unlimited. The stronger the hands of the people holding bitcoin, the stronger bitcoin becomes.

Big institutions jumping in to buy crypto is good but at the same time bad due to the similar reasons highlighted by you. If they have something planned behind the scenes then it could be a major drawback for all the traders/investors.