Wanted to share our experiences in Dec 2021 -January 2022 - hope this helps.
We drove from Portugal to Spain and there was no checkpoint to confirm vaccination status or recent COVID test (this may seem like a silly thing to say for those of you who have crossed borders since the EU was formed but I can still remember the hassles of crossing the borders in the old days).
None of our Airbnb's required our vaccination cards.
None of the museums, churches, restaurants (we only ordered food to-go), or stores required our vaccination cards.
Mask wearing compliance was very high - everyone wore them indoors (except for restaurants) and most people wore them outside also. Big cities had better compliance than small towns. All of our guides were very good about wearing masks and requiring attendees wear masks.
Lufthansa on the flight home required a N95 or KN95 mask.