Google has updated Google Calendar and also may be via server side switch enabled Google Tasks integration inside Google calendar app.
This seems to be rolling out in phases as on my Note 10 Lite I am getting it but on Asus Max Pro M1 it is not yet available.
Finally Google added much requested and basic feature after long time.
So I uninstalled Google Tasks app now.
I prefer using Google apps like chrome, calendar, keep, messages, gboard as they allow you to switch phones more easily among Android phones without worrying about data in specific apps.
Check following screenshots.
