Brand loyalty is probably less important than network effects. NewTechCoin may be way better than Bitcoin but nobody's going to buy it until everyone else is buying it.
While it is the case that most things get priced relative to BTC, and this does have a network effect since you end up exiting to BTC and thus reenforce its price, it's increasingly common to see trading pairs for ETH, LTC, USDC/USDT. There is interest in getting more liquidity into the market and that's a large part of "DeFi". It's not that BTC is self-perpetuating lock-in, it's that they're all growing but everything else is running several years behind, so on a day to day basis BTC still holds relatively more of the market.
Another option is of course that one crypto would just overtake Bitcoin. If I remember correctly this almost happend with Ethereum and was called the flippening. This scenario would be better for crypto of course than a real Bitcoin crash.