Yes, and you can actually over-convert, which nobody mentions. The two real reasons people do conversion ladders in early retirement are access, since converted amounts come out penalty-free after five years and that's how people bridge to 59½, and bracket-filling in the gap years when income is artificially low. If your Roth balances and taxable accounts already cover the bridge, the first reason doesn't apply to you at all, and the second only matters if your traditional balance is large enough that future RMDs would push you into a higher bracket than you're in now. On a modest traditional balance, that may simply never happen. Three arguments do survive a small balance though. IRMAA, because Medicare premiums are income-tested on a two-year lookback and conversions done before 63 never touch it. The widow's penalty, if you're married, since the survivor files single on roughly the same income with far narrower brackets, and that's a real risk regardless of balance size. And heirs, because a non-spouse beneficiary has to drain an inherited traditional IRA within ten years, which lands during their peak earning years at their marginal rate, whereas an inherited Roth comes out clean. If you've got kids likely to be high earners, that's often the strongest case. The other side, and it's the part that answers your actual question: a traditional balance is genuinely useful. It fills your standard deduction at zero tax every single year, it's the ideal source for qualified charitable distributions after 70½, and it's the right thing to leave to charity. Converting everything means prepaying tax on money that could have come out at 0%. So the answer isn't a principle, it's arithmetic. Project your RMDs at 73 or 75 against your expected bracket, and convert only what's needed to keep them from spilling into a higher one.

Don’t convert while you’re still working. For early retirees, generally the math works out better to contribute to traditional while working and convert to Roth when you stop working. For some this is a key part of the strategy because Roth conversion ladder is how they can tap retirement funds without penalty, before hitting age 59.5. For others it just makes sense to use the 0% tax bracket to get the money converted over slowly, without being taxed. So for you: when you stop working, if you have room in the 0% bracket and possibly even the 10% bracket, you might think it makes sense to get the money into Roth, even if you already have a lot in Roth, because why not.

I think it really comes down to the numbers rather than Roth conversions being automatically good. If you already have a decent Roth balance and expect your traditional IRA to stay relatively small, paying a bunch of tax now just to move money from one bucket to another may not be worth it. The conversion strategy seems much more useful when you have a big traditional balance and can take advantage of lower tax brackets during the years between retiring and taking Social Security or RMDs. I’d probably compare the tax you’d pay on the conversion now with what you realistically expect to pay later, including how much room you have in the lower brackets. Basically, Roth conversions are a tool, not a retirement side quest you’re required to complete.