Why Not Pro Games On 4-8 Spawn Big Maps?

Was watching a pro game today on the new 3 player map.

Made me wonder about why the pros basically always play very similar sized 2 spawn maps rather than 4 to 8s...

Made me realize I want to see the best of the best for a million dollars in a tourney with giant maps with 10 potential spawn locations and 800 supply each...

Was watching an amazing Maru first person v Dark today and an awesome Hero / Byun game and I could easily watch 2 hour games of top level players battle it out on giant maps with huge supply caps...

Has this been done before?

Could it?

Should it?

It sounds fun to me...