Everyone's financial situation is different, so each retiree must come to his/her own decision regarding how much income their spouses need and how much risk they are willing to accept.
I retired fairly recently from the USAF (O-5, 20+ years), and I elected to take the full SBP amount. When you do the calculations, there are an incredible number of variables so you must make assumptions in order to come up with valid comparisons ... and the validity only remains if the assumptions turn out to be correct. So ... guess well.
When you calculate how much life insurance you need, an effective way to do it is to figure out how much your spouse would need to invest in an inflation-protected annuity in order to at least equal the amount he/she would receive from SBP. In my calculations, with fairly conservative assumptions, I would need about $1,000,000 in life insurance to cover it. And, if I were to take the life insurance route, I would have to hire a hit man on retainer to make sure I get whacked prior to the term of the life insurance expiring.
For my family, SBP made sense.
Here is what USAA says about SBP:
https://www.usaa.com/inet/ent_utils/...ry_retired_pay
My point is, I would recommend against dismissing SBP out of hand.