This is not true. We have simply adopted a system where it is a feature. We did not have steady enforced inflation until the 1950s. There are entire schools of economics that believe the concept of controlled inflation should be relegated to the past, and replaced with market ruled inflation / deflation.
I'm not saying I understand how such a fictional world will work (and I am a finance professional so I understand this very well already), but people always saying "inflation is necessary" are people with no imagination who don't look at history.
Greenspan thought we'd solved the problem when he realised he could just keep lowering interest rates and growth will keep on happening. Turns out Bretton Woods withdrawal and the stagflation of late 70s gave enough cushion for him to test his hare brained schemes on the world and lead to the explosion of growth that came afterward. And then 2008 happened. Turns out Mr.Yes-Market was wrong all along.