One of the great mysteries of HubSpot. Why is this filter type available in some places but not others. (There is probably a technical reason for this.)
Sometimes you can work around this issue by going through a list (since they sometimes offer more options) but that’s not the case here.
It seems however like you could instead use Date of last meeting booked in meetings tool, that property offers the “is more than” filter.
If that’s not suitable for your use case, I’d recommend taking it to the HubSpot Ideas section of the community. The product team is monitoring the requests submitted here.