Most of the time we would see this happen, whenever Bitcoin drops altcoins would follow with a greater fall, but it wouldn't always be like that there are times that it would contradict the price movement.
There are times that Bitcoin price would fall and the alts would be pumped or vice versa.

By "duplicates of Bitcoin", do you mean "clones"? Well, I'd say there aren't that many clones on the market these days. At least, not direct copies of Bitcoin. What do exist are clones of tokens. Especially those that are based off "memes". For instance, PEPE is a clone of SHIBA. BabyShibaInu, Floki Inu, and a few others are the same. They don't have anything innovative other than a few tweaks "here and there" (like changing the total supply).

Altcoins that are a "true gem" are quite scarce. But worth having in your portfolio. Besides Monero, Litecoin and Ethereum are "undervalued and underrated". I doubt any altcoin will be able to survive on its own without Bitcoin. After all, the latter is the one that started it all. Why do you think BTC is the "reserve cryptocurrency of the market"? Every crypto exchange has at least a BTC trading pair. So if BTC goes all the way down the drain, altcoins will lose their value big time. Just diversify your investment to minimize risks of loss, and there shouldn't be any problem.

They are all part of one market. Liquidity just pours from one to another, I would see it like that.

That is right that liquidity pours from one cryptocurrency to another as they are part of the broader market. But liquidity is not fixed. There can be an added amount of liquidity. There can be more investors or traders entering the market through bitcoin. Those who want to get into the crypto market but does not want to get into bitcoin will look for others and that is how bitcoin "decides" the fate of altcoins. Some times, people see altcoins as an extension of bitcoin and if bitcoin is doing well then so must altcoins then.

It's bigger than altcoins, which is correct; it also holds a larger portion of the entire market capitalization, but that's not the only reason. To some extent, some of these altcoins are paired with Bitcoin in terms of trading them, which means if the price of Bitcoin drops, it will also affect their own overall value, and as the king of all other currencies, once the king is affected by something, it's likely that every other currency will get the influence, but there are rare cases where some few altcoins show some resistance, but not for long.

I still remember the last bull run. Where the public was regretting not being able to buy Bitcoin. And then later those who made the same mistake a second time. But if you think about this cycle, you will see a common pattern. Before, by the time Bitcoin reached 50,000, the bull run had almost started. But this time it was something completely different.

Now if you look closely you will see that only Bitcoin investments are happening. That is why Bitcoin dominance is increasing. And it is a universal truth that if Bitcoin dominance increases then the bull run of ALT coins will not start. Because no one is willing to invest in Alt coins now, everyone is eager to invest in Bitcoin.

Everybody waits for liquidity to pour into the maximum capacity it can be: afterward, the target would be the altcoin world.

And we didn't reach the biggest ATH yet

I agree with you that if bitcoin dominance continues to increase there will be no altcoin season, and that is exactly what is happening, and it is making altcoin investors unhappy. But if you look at previous bull runs, you will see that bitcoin dominance always increases before crashing. It can't go up forever and at some point bitcoin will give way to altcoins. It is all a matter of time and all altcoin investors need to do is wait.

I don't know when the altcoin season will come but I believe bitcoin dominance will crash at some point and that will be the era of altcoins. This is the crypto market which includes bitcoin and altcoins, not a bitcoin specific market.

Bitcoin is at lead when we talk about cryptocurrency as it has the tendency to appreciate over time, bitcoin has been tested and trusted and has also stand toll among other coin.

Well, if we compare with previous cycles, there is no denying that things are changing. During the cycle and so far, bitcoin has completely dominated the market and altcoins have barely had a chance to shine.

But to be fair, if we still believe that history will repeat itself, the bull season is not over yet and bitcoin will hit $150k or $200k this year. It's too early to say there won't be an altcoin season. We should wait until the end of the year and if nothing happens with altcoins, we can say that everything has changed and the game is only for bitcoin.