> Yeah, a quick script in a cron job. Oh, but now we need 2 pages monitored. Now we need 100. Now provide an interface for marketing to add and remove pages. Make sure it emails these N people (different for each page of course!). Oh, this has to be up 24/7 so we'll need a server and monitoring and a test environment and deploy strategy. Your script is giving false positives because of changing asset timestamps. Oh, your script needs to provide a visual indication of what changed and when. Etc etc etc et cetera.

> I recently used a similar site (visualping.com) to score a pair of airpods, which are in tight supply, by watching my local apple store for availability. Worked beautifully. Write my own script, are you kidding?

You are totally conflating use cases. For most people, monitoring 2/3 things, a cron script works fine. In fact, I have one that's running right now and it Just Works (TM). By the time I need to provide visual diffs and have bulk email logic, I'm probably going to use an external tool (or whip it up as a side project if I think it's worth my time).

You can't equivocate the n=1 case and the n=10000 case.