Should I invest in a Trad IRA if it is not deductible?

[Olav23]

I am unable to invest in a ROTH due to my AGI being over the upper limit. I am also above the limit to deduct any portion of a traditional IRA, but can still put in the max of $4k each for my wife and I. (8k total)

Should I do this?

I assume there is a benefit to the tax-free growth above and beyond the initial deduction?

I already max out my 401k, but my wife has no retirement plan currently.

Thanks!