> are we better off sticking with a consistent savings+interest

Nothing about your savings account is consistent, just last year you would have struggled to find anything above 0.5%. Your future savings account rate is just as temporary and unknown.

> I was planning on leaving them for the full 30 years, but it seems like people who understand this stuff far better than I do choose to take them out at 5 years?

Generally speaking, inflation has not been very high in the US. The last period of high inflation was the 1970s. The last decade of historically low interest rates has been driven by the federal reserve struggling to get inflation to reach 2%, and failing.

The general expectation is that there will not be long term high inflation in the US, basically nobody expects there to be. In that kind of environment, holding I bonds for the long term would be a poor choice, and so nobody is really planning on doing so.

Luckily, you can choose to redeem whenever you want (at least, after 1 year), so at any time between now and 30 years you can adjust your strategy.