Baseball is supposed to be played outdoors. No domes.
If I were the Commissioner of Baseball, I would order every team to play with the roof open. If that's not physically possible, given their current stadium, I would give them one year to get a deal done to build a stadium without a permanent roof, and then three years to get it done. Any team playing a game with a closed roof after April 1, 2028 would forfeit that game to the visiting team.
This would also apply to artificial turf, although that should be considerably easier to replace.
Don't tell me you can't afford it. Every MLB team is owned by a man, or a group, that can build a dozen or more new stadiums without one damned penny of the taxpayers' money.
"But what about rain?" And, "What if it's cold?" Postpone the game, and make it up later. If you need help with rescheduling, notify the MLB office, and we will accommodate you.
"But that would make the doubleheaders pile up!" So? Play them.
"But that would be a terrible inconvenience!" You're getting paid millions, team management. Suck it up.
"But it will exhaust our pitchers!" No, what exhausts your pitchers is not letting your starters pitch 7 or more innings. Trust your starters.
"But what about the fans?" Oh, so now, you care about the fans? The fans will be fine with the doubleheaders. Heck, they can plan day-long parties around them, like that other sport does with its Super Bowl.
MLB Domed Stadium History:
Houston: 1965-1999, Astrodome. Permanent Roof, with Artificial Turf from 1966 onward. 2000-present, Enron Field/Minute Maid Park. Retractable Roof with Real Grass.
Seattle: 1977-1999, Kingdome. Permanent Roof. 1999-present, Safeco Field/T-Mobile Park. Retractable Roof with Real Grass.
Minnesota: 1982-2009, Metrodome. Permanent Roof.
Montreal: 1988-1998, Olympic Stadium. Retractable Roof, with Artificial Turf. Roof had to be removed due to ineffectiveness.
Toronto: 1989-present, SkyDome/Rogers Center. Retractable Roof with Artificial Turf.
Tampa Bay: 1998-present, Tropiciana Field. Permanent Roof.
Arizona: 1998-present, Bank One Ballpark/Chase Field. Retractable Roof with Real Grass until 2019, then switched to Artificial Turf.
Milwaukee: 2001-present, Miller Park/American Family Field. Retractable Roof with Real Grass.
Texas: 2020-present Globe Life Field. Retractable Roof with Artificial Turf.