From my experiences, I personally believe that there is no such thing a better rack. Hence, the only reason why you should choose one over the other is based on specific products and your personal preferences.
That being said, in this post, I’ll be talking about the advantages and disadvantage of having each of these racks. Depending on your requirements, you can find out what type of rack is more suitable.
Here you’ll find the most common advantages of having a trunk strap mounted bike rack and hitch bike rack, respectively.
Trunk strap mounted bike rack
The best thing about trunk mounted bike racks is that they tend to come with minimal requirements. All you’ll need to do is mount the two upper hooks on your trunks, then move to the side hooks. Tighten all the strap and you’re done setting up the trunk strap mounted bike rack. No additional equipment is required to complete the setup.