There's a bunch of things about 'being in an office' that aren't so much about 'being in an office' as they are 'not being in your house'. Cynically, you could point out some power dynamic - symbols of you being part of something 'larger' than yourself are often parts of offices (big or small), and you're submitting yourself to some rituals shared by your colleagues and (many?) others in society.
BUT... there's also less responsibility for maintenance - offices often will have cleaning/maintenance, decent hvac, etc. They can provide a standardized work environment that helps legitimately separate 'work' from 'home', which many people need help in doing (even pre covid).
Yes, you get the big whiteboards and maybe other equipment that just doesn't make sense for a home (big copiers from decades ago, etc) as well.