Apple calendar stopped showing events on Mac
Indeed, it was a more wide-spread and general issue with Google.

However, I had opened a formal trouble ticket with them, which eventually got recognized, acknowledged, escalated, worked upon and resolved, by about 10:30 am PST 8/23/19. 

However, you may need to still purge your calendar cache files: 


go to calendar.app, go to settings, go to accounts, uncheck the calendar to disable, then quit the calendar application.
then, go to your User Library folder ( ~/library/calendars/ folder), 
(you can easily lookup how to do this if you don't know how to find it)
then, delete all items with the name "Cache" in it such as:
Calendar Cache-shm
Calendar Cache
Calendar Cache-wal
go back to calendar.app, launch/run it, then, go to settings, go to accounts, check the calendar to re-enable your Google calendar account
Then finally, you may wish to also click CMD-R to refresh calendar data and wait for enough time for all data to re-sync