They grow all kinds of food indoors nowadays. So Im sure they can do it with grass. I’m not sure why they don’t.
it is about $, the billionaires go with whatever costs the least. Cost effective is the way to more profits.
Grass fields cost more to set up and maintain and that comes out of the owners pocket.
The only way would be if the nfl as a group were willing to fund all stadiums to have real grass fields.
Most today are the rubber fields where u see the stuff come up when a player drags their foot for example.
In the first game with dallas ny ,you could see the rubber bits on players faces due to the rain.