Your assertion that it's "flat" is rather unconvincing after looking at that graph. It's clearly been rising relatively consistently. The dip for covid I think is especially understandable, and it's currently higher than it's ever been.

Maybe your personal expenses are not reflected by the CPI, but you can see for yourself: https://www.bls.gov/cpi/tables/relative-importance/2025.htm

44% housing, 8% medicine, 14% food. I don't see how these number are manipulated to the point of malicious data picking. They also publish their methodology.