Naming things is hard[citation needed] and there are a lot of things that you can name when configuring a Drupal site. Picking the right machine names for the different parts of Drupal can make your life easy in the long run. Changing labels is simply a case of tweaking the label in the interface, or through configuration updates. The issue is that once you decide on a machine name for something in Drupal it's pretty much set in stone forever.
The machine names you pick are often used in database tables, paths, interface elements and pretty much anywhere it is used. Changing entity or field machine names at a later date is difficult and can mean writing complex code or using migrations to achieve.
Read more here: https://www.hashbangcode.com/article/drupal-9-selecting-machine-names-content-entities-and-fields