I suspect some of the OG crypto millionaires like to give away small amounts of their fortune to charities because as well as being tax deductible, it avoids capital gains taxes, and promotes use of cryptocurrency (increasing the value of the rest of their holdings).
The Catholic Foundation, which is part of the Archdiocese of Denver takes crypto, and has a whole page about the tax benefits: https://thecatholicfoundation.com/crypto/
"Donating cryptocurrency is a non-taxable event. Donors do not owe capital gains tax on the appreciated crypto that is donated and can typically deduct the fair market value of the donation on their taxes."
If you have $1000 worth of crypto that you bought for $100 and donate it, you have $0 worth of crypto (because you gave it away) and e.g. $400 (assuming a 40% marginal tax rate) worth of tax savings.
If you sell the crypto instead and keep the money, you pay e.g. 33% (20% federal + 13% California) taxes on it, and you have $0 worth of crypto (because you sold it) and $670 worth of cash after taxes.
If you're assuming 13% California, that's $1M annual income. You should assume 37% marginal federal tax rate for deductibles, and assume 23.8% federal tax rate (due to NIIT) for long-term capital gains.
Therefore, donation generates $497 of value (37%+13.3%=50.3%) whereas selling and keeping generates $632 of value (23.8%+13%=37.1%). Therefore, the difference ($135) is quite a bit smaller than your math ($270).