Very useful. They have the ability to send a wave for a short distance to see what is around you that is a threat, also they can scare away small creatures (raptors, pegomastax e.g.). And they have good weight capacity and very easy to tame, this is definitely a good mount.
The parasuar has had its base damage buffed to 12, base weight buffed to 480, and it’s wild weight gain was raised to 9.6 per level. This makes parasaurs carry only slightly less weight than a mammoth. Parasaurs have had a huge buff.