With a lunch and learn when everyone is at the office, you kill two birds with one stone. Learning is a good thing and it's sometimes hard to find the time otherwise. And by offering catered lunch you get bonus points/goodwill/whatever with the employees.
During WFH times this is absolutely the opposite. You're trying to make me work during my lunch now and you don't even buy me lunch! (and no, sending me a pizza voucher or something does not make it better. They don't deliver here anyway.