That is a graph of the official exchange rate, set by the government and not moved by the market

Every day the government moves devalues the peso gradually.

If you search for a graph of the market valued dollars (MEP, CCL, Blue, etc) you'll find they look a lot more spiky

This one in Alphacast (a platform for economic data) compares the blue dollar to the MEP dollar https://www.alphacast.io/p/lisandroiriarte/charts/dolar-mep-...