What loan rate is threshold for investing in broad market instead of paying off?

I have a number of loans with varying rates (2%-8%) and just came to enough $ to potentially pay them all off, or invest. What would be the threshold % loan rate for investing instead of paying off.

For context, I have no other debt, and already max out on pre-tax account so any investment will be VOO/QQQ in taxable account.

Loans total 6 figures and will otherwise be paid off in 5 ish years.

I am about 15 yrs from retirement and already have emergency funds in SGOV (~4% Div currently).