It should be an exclamation: What people are doing these days !
It would be said by someone, probably getting on in years, who is commenting on the activities of people now, compared with years ago when this speaker was young.
eg commenting on the number of people getting a divorce at the drop of a hat these days, compared to decades ago when people stayed together through thick and thin.
As a question, the word order would be:
What are people doing these days?