Can't accept or decline emailed meeting invitations in iOS (but can in MacOS)?

Hi - this seems to have been a bug for many years but still not fixed. I even lodged a bug report with Apple last year but nothing seems to have been done.

The issue is accepting or declining calendar invitations emailed from someone using Microsoft Outlook.

Opening the email in iOS Mail you'll see a .ics attachment. You can open that attachment and save it to your iOS Calendar. But there are no buttons to accept or decline that invitation in iOS, either directly from the Mail App, or by opening the invitation in the Calendar App. This is how the invitation appears in iOS when opening it from the Calendar App:

The only possible action iOS permits is "Delete Event".

However in MacOS, opening the same invitation in MacOS Calendar, the "Accept", "Decline" and "Maybe" buttons are shown and can be actioned. It is also possible to add a comment to be sent back to the meeting organiser:

Am I missing something really obvious here, or is this a known bug/omission?

It is really quite annoying to not be able to accept or decline emailed Outlook calendar invitations from within iOS Mail or Calendar.