In my opinion as well, altcoins are not having their own way of price movement but they are simply following bitcoin market; an altcoin's market movement can be directly proportional to bitcoin or invertably proportional to bitcoin market but when there will be a significant chance in bitcoin market then that will reflect in all altcoin's market...
Since bitcoin has less volatility compared to altcoins, when the market is dumped, its price decreases less than the altcoin price. Therefore, in a bear market, investors sell their assets and buy BTC. But with a bull market, good altcoins have more chances to surpass bitcoin in profit.
That's why we must be able to make the right decision according to the conditions at that time so that it can generate profits,
even so making a decision is also not an easy thing we need to research the coin and the market first and that is the important thing