... I would like a feature to able to Hide Topics/Messages.
I think this is a good suggestion, as I don't think the feature exists (yet).
In the More menu under each message is a Report This Message item which can be used to report the message to the group moderators or to Groups.io Support. Maybe that function should have an option (available only to moderators) to also hide the reported message from the view of members.
See also Hide Topic Function for an earlier request of this feature.