I bought I Bonds this year and last year before the latest rate drop. Looking at next year, it's possible I might buy I Bonds at current rates. The main selling point would be if 0% real, less taxes, might end up earning more than say online savings accounts or CDs over time. That would essentially mean inflation outpacing near-term rates, although right now most people are betting on there being limited inflation for some time. When I started buying I Bonds, my estimate was that they may have made sense compared to online savings in the years since the 2008 downturn, including the deflationary 0% nominal return months. Tax deferral for I Bonds also came into play in the backwards looking comparisons I attempted before buying.
With rates being so low on near-term investments, it's possible that I Bonds could turn out to be more useful than some alternatives. Earning around $100 per year on $10k has little appeal to me compared to say early 2019 rates. The only reasonable rates locally don't fit personal preferences, and I'm generally not interested in bank bonus chasing, so I figure I might as well just buy inflation protection with the near-term reserves I keep (maturing CDs).
My thinking regarding I Bonds and EE Bonds is generally in line with the reasoning given by David Swensen in Unconventional Success for recommending inflation protected and nominal government bonds. I figure savings bonds seem reasonably in line with that outlook in the current environment. I'm not interested in using my tax-advantaged space for TIPS, and don't have a need for more than I Bond limits, so I don't have any reasons to personally buy TIPS at recent rates. I usually tend to also agree with articles from the following.
Targets: 15% I Bonds, 15% EE Bonds, 45% US Stock (Mid & Small Tilt), 25% Ex-US Stock (Small Tilt)