How can I get Siri to add alerts when it create appointments?

What that means is the vast majority of the 800 million iOS users don't think it needs fixing. When there are strong opinions about any functionality that exists or is missing there will be thousands of posts about it, both here and on other technology websites. And even the OP was satisfied with the way it works. If it was an issue recognized by others this thread would be 50 pages long by now.

You need default alerts set up for the Calendar - go to Settings, Mail, Contacts and Calendar, scroll down to the bottom and you'll see it

Unfortunately, by defaulting calendar alerts on iPhone, that default will be added to all appointments. So, if the default is 5 minutes and you add an appointment on the mac without alert, you'll get a 5' on the iPhone. If you add an appointment on the mac with 10' alert, you'll get both a 5' and 10' alert on iPhone...

Jet787 wrote:

Unfortunately, by defaulting calendar alerts on iPhone, that default will be added to all appointments. So, if the default is 5 minutes and you add an appointment on the mac without alert, you'll get a 5' on the iPhone. If you add an appointment on the mac with 10' alert, you'll get both a 5' and 10' alert on iPhone...

That's correct. And I'm sure it helps those users who posted the question 4 years ago.

😊 ...and if you think it is quite weird that this simple issue has not been fixed yet... ...4yrs! Tnxs.

No worries, however from my point of view it is not exactly as you say: simple issues do not necessarily move thousands of people, but it would be nice to have them fixed anyway if possible, especially if they are easy to fix, in case this is brought to the attention of appropriate people.

Even 1 single message or report could be as valuable as millions of posts. There are no stupid questions.

That is one of the thousands of reasons why these Apple products are heading for excellence.

However, I fully respect your point of view, as you are doing with mine.

Have a nice day.

The best way to communicate with Apple is http://apple.com/feedback. They don't respond, but they DO read the messages, and if they see a trend they frequently act on it.