Are Sharepoint REST APIs legacy?

Hello, I am new to software development and confused about two things. I would appreciate your help. There are links on Sharepoint documentation site for https://learn.microsoft.com/en-us/sharepoint/dev/sp-add-ins/get-to-know-the-sharepoint-rest-service?tabs=csom and https://learn.microsoft.com/en-us/sharepoint/dev/apis/sharepoint-rest-graph. When I click on the second link, it gives me an option to go to the legacy version, which then takes me back to REST API V1. The second link on REST API V2 includes Microsoft Graph API.

Now, else where in the Sharepoint Framework documentation, there is another https://learn.microsoft.com/en-us/sharepoint/dev/spfx/connect-to-sharepoint that talks about how to connect to REST APIs. So my questions are:

1) What is the deal with Sharepoint REST APIs. Are they legacy or not, what is legacy about them?

2) Is it fair to say if somebody is developing a new application, one should use Microsoft Graph API, or there there are some scenarios where REST APIs would make more sense?

Thank you.