Question about DisplayLink Manager requirement for macOS

[steven-]

I have a Dell Docking Station (D3100) and have been using DisplayLink Manager on macOS for a while. I used to have two monitors, and the DisplayLink Manager enabled me to connect two monitors at the same time with my MacBook Air (which is something Apple disabled). So I was under the impression that it is only required if I need to connect more than one monitor.

Right now, I'm only using one monitor with HDMI, I found that all my connected USB-A devices still works with my MacBook without the DisplayLink Manager, but I still have to run it to connect it to a monitor.

Is this normal? So you must run the DisplayLink Manager if you want to connect your MacBook with a monitor? What if I use DisplayPort instead of HDMI?