Every year my employer has a well-being day for staff. It's a paid day so everyone has to engage or if not they have to go into work. Unpaid is not an option. We are given choices of many activities to do with colleagues which people organise and we have to self fund them. They range in cost and some are obviously free.-Spa days or theatre visits, hiking, trips to the beach etc. However we are not allowed to just do our own thing. We also have to prove that we are actually at the activity we have chosen to do, (registers are taken)
This differs greatly to friends who employers let them decide what they want to do on such days.
AIBU to not want to spend my well-being day with my work colleagues doing activities when I'd rather spend precious time with my toddler and grandma for example or having lunch with a friend etc.