FWIW though, after one wire transfer on Gemini they will let you ACH transfer back and forth with the account you wired from. It works pretty well. (However, watch out for fees by using their Gemini ActiveTrader interface, similar to using Coinbase Pro vs Coinbase).
You can also use Plaid to link a bank account on Binance US, but it seemed buggy when I tried it. However, if that worked it would also allow ACH deposits and withdrawals.
I haven't used FTX US, but it looks like they also have Plaid integration that should support ACH deposits and withdrawals.
Wire transfers do seem to be the best option for deposits and withdrawals on Kraken. Some other options, including ACH, are available via their Buy Crypto widget (but it has higher fees, and apparently you can't withdrawal later via ACH).
Anyway, if you want another fiat gateway that supports ACH deposits and withdrawals, and you're fine doing one wire to authorize a bank account, maybe check out Gemini.