Question about Opportunity Amount

Kind of weird thing first time I came across this because my client changed the opportunity amount field in the lead to something else and wondering why it doesn’t sync to the opportunity on conversion… but…
The Opportunity amount by default in the LEAD is opportunity_amount which is a text field???

Then on conversion it becomes a currency field in the Opportunity called amount.

Just wondering why this isn’t like every other field that carries through on conversion where the field type and the name are the same in the lead so it automatically pushes through on conversion. Also, I’ve never run a report on Opportunity amount for leads, but it would be better as a currency.

I know how to solve my immediate problem, just looking for some discussion or rationale.

I think there’s specific code for these things in the conversion process…