Altcoin will always exist, it can't be Bitcoin alone. This will even be boring. I will always advocate for a healthy competition, and not a monopoly. And of course, Bitcoin is at a distant gap winning altcoins, and this will likely remain forever. But this doesn't mean altcoins will cease to exist, some will. Similarly to what you said, what I envisaged is that all sectors of altcoins (L1/L2, AI, DeFi, meme etc) will have their coins/tokens holding well, no matter how little, forever.
Agreed.
BTC is there to show that others may lack or not lack: it's like the same with fiat in case if it were only BTC on the market, alternatives are needed everywhere.