A developer chooses which media breakpoints to use depending on what platforms they are designing the website for: desktop, mobile, or tablet. However, it's increasingly important in today's world that websites have a responsive design and have multiple breakpoints designed for all three of these devices.
According to Kinsta.com, the ideal minimum width for a desktop is 1024px, an ideal minimum width for a tablet is 768px, and an ideal minimum width for a phone is 767px. These pixel widths do match up fairly close with the breakpoints that were used for the project in Lesson Plan 6. In addition, the breakpoints from Kinsta.com match up exactly with the breakpoints listed in an article at Labdatest.com for creating a responsive website. With two articles stating the same breakpoints, a developer can be confident in creating a website with these breakpoints.
Sources:
https://kinsta.com/blog/responsive-web-design/
https://www.lambdatest.com/blog/how-to-use-css-breakpoints-for-responsive-design/