I have been asked to set up an announcement list and set other users to
automatically receive alerts (but be able to disable alerts if they so choose).

I know as a site administrator, I can add an alert on a list and I'll have a
field to enter other users who should receive alerts. However, I'll be doing
this for a little over 2000 people so I doubt that will be a good option.

I've been looking into how to do this via powershell and I think I'm mostly
there but I'm curious if there are better ways to go about this task.

Also, I would be interested in any experiences/concerns with regard to
configuring a list to send alerts to over 2000 different users.