True, you got a point, but consider: Saying a few words at lunch time can become a kind of automatism quickly. Perhaps inviting people to social time going out to eat somewhere will leave a more lasting memory. It might not be for everyone. For example people having children and all that. But it does give people a chance to be in a setting outside of work, but with people from the job, which might give a chance to bond through other topics.

I think there might not be the perfect reward/thank you for everyone.