While I agree with that in premise, unfortunately in crypto things move so fast that if you tried to become an expert in anything before dipping your toes in the water, you end up missing out on lots of movement. Personally, I find there's no better incentive to learn the ins-and-outs of a new blockchain than to just buy a bit and play around with it. Any money lost I just look at as tuition.
To your other point, while BTC's position of supremacy is still undisputed, I think there's quite a bit of indicators which suggest that position is indeed in jeopardy. Maximalists swear that any day now Bitcoin will be able to do anything and everything currently possible in the cryptosphere, yet to this day the blockchain only performs three functions: sending, receiving, and storing Bitcoin. And really, that's all it needs to do to survive as an extremely valuable digital asset long into the future.
But the rate at which Web 3.0 is being built out is astonishing, and Bitcoin plays no role in that other than as defi collateral. I will not be surprised to see BTC dominance drop to 20% by the end of the year.
No disrespect. BTC to the moon ✊