I doubt there’ll be any significant value locked in RSK/Sovyrn, when most of the liquidity is on Ethereum. Plus, it’ll take time for BTC developers to learn Solidity, and most of the DeFi network effect will be on Ethereum and other EVM compatible chains.
ICO is just a way for startups to raise money (though lately, it seems to be more about governance tokens once they have their project up), DeFi is a way for people to lend and get loans, trade margin, synthetic stocks, and NFTs empower creatives to make money off of their work and people buy them because they enjoy it and also see them as long term investments just like in the traditional art world.
Are the prices ridiculous? Sure, but so is Bitcoin during bull runs. Things will settle during the next bear run and tokens will likely reflect more realistic prices.