If you design for email alerts you invite reply loops, permanent delivery failures, and all the headaches of scaling SMTP. RSS, while nerdy, offloads almost every operational hassle to the client and works fine for polling when instant delivery isn't mandatory.

Some users want to pipe these updates into scriptable things like Slack, bots, or custom dashboards, where RSS is much easier to handle than email. If you offer both, people will use whichever fits their workflow, and that isn't always predictable.