This is not true for all crypto coins. A small proportion of mining hash functions are deliberately designed to thwart ASICs, e.g. https://github.com/tevador/RandomX. It's a cat-and-mouse game, though: CryptoNight was designed to fulfill the same role, but ultimately failed: https://monerodocs.org/proof-of-work/cryptonight/.

Depends on the cryptocurrency. Some are designed to be intentionally difficult-to-impossible to optimize with an asic, with Monero being the big one I think is most well known.