I would not suggest high school's should be Mason sized, but I think schools can offer better options when a school is large enough to have the varied staff and teachers that allows.
A 1,000 seat high school would be better than 100, but 2,000 may be too much.
Various research has suggested that the ideal student population for learning in grades 9-12 is somewhere between 600-900 students. Data suggests that schools smaller than 600 students learn less and that schools with enrollments over 2,100 see similar results. Schools do reach a point of diminishing returns.
The school I teach and coach in is a tick over 2,000 students in 9-12. When I first started here we were a trick over 1,000. This was 17 years ago.
One thing people fail to realize with big schools is a segment of your students will get lost in the shuffle. Believe me I see it every day, week, month, school year, graduating class, etc... The "small schools" initiative that began back in the early 00s was designed to create schools that fostered healthier relationships among teachers and students who by design of a smaller school create greater teacher / student connections and as a result create greater degrees of student learning.
People often times scream that consolidation will reduce costs. In fact, getting rid of a superintendent will only save that cost but create a need for more custodians, food service workers, bus drivers, teaching staff, etc.... Athletically combining schools would possibly result in greater opportunities, but with those opportunities comes the need for additional athletic funding.
Wando High School in Mount Pleasant, SC just two years ago had an enrollment of over 4,000 students but still only fielded a football roster similar to schools in the Charleston area whose enrollments were half that. There is no proven statistical correlation between school size, offerings and increased participation.
Lastly, large schools like mine do not have an overall identity. We have multiple cliques within the school that sometimes do foster division among the student body. It gets worse when you begin talking about consolidating different communities. My school represents 7 different zip codes and communities. The older / original community I know has felt push aside over the years as the school has grown and changed demographically.
Lastly, as a teacher, with each passing year a few of us "old guard" have a running gag that we work with people who if you put a gun to our head and said "who is this?" you'd have to shoot us. TBH I work with people who I don't even bother to even know their name for a variety of reasons.