Greater Fool Theory underpins crypto currencies. NFTs are a variation on them designed to evade securities regulation. With crypto pogs you're either the con man or the mark.
These are speculative 'assets' that can only be traded for another speculative asset (altcoin) or a 'stablecoin' that promises that each coin is backed with US$1, but refuses to conduct an audit to verify it.
The original promise of crypto was verifiable, trust-less, decentralized transactions of value without middlemen, sanctions or high fees.
These transactions have different properties, whether alt-coins, BTC or Ether; for example:
* Transaction speed can be Fast / Slow
* Security - Very Secure / Broken
* Centralization - Tends towards decentralization / Centralization
* Transaction cost - Fee-less / Extreme
* Privacy / Transparent - Opaque
* Energy Efficiency - Highly Efficient / Purposefully wasteful
Some alt-coins have far, far surpassed BTC and Ether in all of the above. However, the people who hold BTC and Ether were there first, made the most, and have no intention of letting that value go.
If cryptos are nation state currencies, BTC and Ether have invested their money in defense and propaganda. Alt coins are a mixed lot, but some of them have greener, faster, more sustainable and less centralized methods. The small citizenry is what holds them back despite technological superiority; for now.
The funny thing about that analogy though, is that changing your backed nation state takes less than a second...
Yes in the short term. Picking the best tech is disincentivized, because there are many and powerful forces beyond technical characteristics at play.
No in the long term, because technology really does matter once people actually try to use the coin. Ether was once the best tech, and it was $10 a coin. Now it isn't, and it's >$4k.
For example: More and more of the people who make money using their graphic cards to mine Ethereum are choosing to have their payment transferred in Nano, and other alts. It just makes more sense to go with the fee-less and near-instant option, when there's a choice like that to be made.
It's not always the company with the best technology that wins. There are lots of different factors that influence that.
That's not to say there aren't greener alternatives out there (especially with Proof of Stake networks), but some of these coins claiming to be greener are only that way because they're not used anywhere near as much.
There is no theory, each one is different. Some propose different ways to do transactions, or different scaling solutions, different governance, different ways to do smart contracts etc. Some are poor solutions, others are outright scams.
BTC and ETH aren't special, they're just big. BTC has the market place it has because it was first, not because it's better in any technical way. Similarly with ETH - it has a large community but it isn't necessarily better at smart contracts (or it might be - people will argue about this indefinitely).