A Roth IRA, whether using the regular or back door technique, is categorically better than taxable in terms of minimizing your tax bill over time.
In either case the income is taxed before you put in - so you have the same amount of money to invest. But, with a taxable account, any dividend or capital gains distributions will be taxed along the way and you'll owe capital gains tax down the road at withdrawal time if the investments have grown. Qualified Roth withdrawals result in tax-free growth as well as at withdrawal time.
The main reason to prioritize taxable over a Roth IRA would be if you need better withdrawal flexibility in the short term, although then the question might be whether you should be investing vs. finding a savings account or other very low-volatility thing to park the money in. Also if you've got existing tIRA money out there that you cannot roll into a 401k or similar to set up for backdoor Roth technique.
But from what you've listed here, you currently are going all the way down to "invest in taxable" - seems likely to me that you're just leaving tax advantaged space on the table for no good reason. Roth contribution is relatively low amount of money at $6,000 (plus possible catch-up depending on your age) per person for 2022 - surely in the 35% bracket you can afford to make this contribution and also make some taxable investments as well, no?