You are conflating cause and effect. Security budget of Bitcoin is defined by block reward. Miners just compete to get a larger piece of the pie. Bitcoin price (and thus security budget) are so high because Bitcoin is the default-go-to cryptocurrency. Media talk about two CCs: Bitcoin (in serious tone) and DogeCoin (as a joke). That what explains Bitcoin domination over all other CCs - dumb money.

Unless you are saying that folks who started 'stacking sats' during last two years are a bright bunch and they are capable of reasoning about CCs security.

> Why does every proposal without miner majority support fail?

Watch miners getting owned during Ethereum's transition to PoS.