A different unit of account
Did things get more expensive, or did money get smaller?
Denominate shows the same everyday things in two units, over ten years, so you can see which one it was.
The same thing, two units
Ground roast coffee, 1 kg, 2018 to 2026
The same coffee reads up 117% in dollars and down 54% in bitcoin. Source: US BLS Average Price Data, delivered by FRED. Reference rates, not executable prices.
Every price shows its source, and whether it is observed or an estimate.
A price tag is also a question of opportunity.