What are some of the benefits of going with a bigger structure over a smaller structure?

Budget often dictates that someone needs to start small, especially when a person is just starting out as a grower with a greenhouse.
There is also the perceived notion that staying smaller means less heating cost. In itself, that is true, since heat loss is in direct proportion to surface area exposed to the outside.

As I have mentioned before, it is very important to weigh expense
against return.

A smaller air volume has less natural circulation.
Proper air circulation for plants is critical regardless of the season.
Think of a deep pond versus a shallow pond. The deep pond never has algae on the surface because of the increased movement.

Going with a taller greenhouse will automatically increase the circulation the same way.

Another point to consider with a taller greenhouse, is that there is more open space above the plants.

This open space is where moisture can go, away from the plants even before the greenhouse ventilation system does its job.

With a lower greenhouse, moisture is always in close proximity to the plants. In a taller structure, the plants will be dry much sooner.

Moist plants in a stagnant air mass are prone to disease. These plants will, as a result, produce less.

As always, be aware of the bigger picture.