Automating Salesforce Data Imports with Powershell and the Salesforce CLI

Some years ago I wrote about using Powershell to automate the Salesforce Data Loader, the idea being that sometimes you dont want to use an ETL tool (think graphical interface with boxes and arrows and properties dialogs - like Talend or Azure Data Factory) to load data into Salesforce. Sometimes you want to do it with some code or scripts, where you can have low level control of all the details, and maybe track the changes in git.