Thanks for describing a (nowadays) common experience of quitting a remote job! I experienced something very similar upon resigning a job that I enjoyed. My coworkers were great and I’ll miss them! But quitting was indeed a lonely process.
I have an HR certification and, although I wasn’t working in the HR department, I agree with all the suggestions to properly send an employee off. Especially because those ex-employees can become your clients or business partners in the future. And what if a few years down the road they become a hiring manager for a job you really want? Your every action today will influence their behaviours in the future.