If you ask anyone why you buy altcoin, you will find that the main reason is financial reasons, either because of staking or because of investment, but the motives for using Bitcoin may be much deeper than that not noly investment but exchange to fiat money, or due to the decentralization of the network, or as long-term savings.
In most altcoins, you find that development takes place at the beginning and then the project turns dead because the developers and primary investors have reaped profits. Therefore, you rarely find projects that have continuous development, unlike Bitcoin, in which almost every year there is either an improvement in scalability or an improvement in privacy.
You do have a point, I buy altcoins to enrich myself in the next bull market, because altcoins has the ability to make me more money than Bitcoin and I buy Bitcoin also to make some money and I am int Bitcoin for storing my funds, safer from inflation and with the package of decentralization I can't go wrong with Bitcoin ever, still altcoins are on my radar, those 100x to 1000x are still real and they always happen, that isn't coming from Bitcoin ever again.
You are wrong when you said that people invest in altcoins because of financial reasons, even whales and VCs are into altcoin investments as well, this is where the real money can be made, with $100 in a good altcoin you can make thousands of dollars, try that with Bitcoin and see what happens, Bitcoin is safer and still profitable on the long run and altcoins are more risky but also have higher ROI potential.
The problem people have with altcoins is putting their eggs in one basket, that's best with Bitcoin but not altcoins, because alts carries the biggest risks of all, they can pump now and dump forever, but the risk to reward ratio is just worthy for me, diversification with minimal amount of money in altcoins will win you a lot of money.