Hello, I'm an end user like you. They didn't remove the feature and it should work. I think you will need to check a few things:
#1 Make sure your settings in the app haven't changed and that in the NOTIFICATIONS section (in the GEAR icon) it is set to send a notification to your phone when someone hits the button. Here is a link that might help you.
https://support.google.com/googlenest/answer/9244826?hl=en&ref_topic=9360533&sjid=920916529318169720...
#2 Make sure your GOOGLE HOME app on your iPhone is up to date. The easier way to do this is to go into the app store and search on GOOGLE HOME. It will most likely be the 2nd one in the list that comes up. You then to to actually select the GOOGLE HOME app like you want to see all the details. It will either have the word OPEN (which means you are up to date) or it will have an UPDATE button in which case do that.
#3 Then next thing you might try is temporarily installing the app on the phone of another family member or friend and see if it rings on their phone.
Hopefully this will get you fixed up. If not come back and let me know some more details. One thing I would want to know is how old is the doorbell? Is it more than 3 years old? Does everything else work okay? For example if someone rights the door bell can you see their image and successfully talk to them?
