Easiest solve for that is just cut down the number of players at your table. That way you can have long turns that come back to the player faster and therefore reduce their boredom.Bored Players or Long turns?
But I suspect too many DMs want to have more players at their table for whatever their reasons... and thus those DMs want turns to be so short so that they come back around to each player as fast as possible. But that really means those DMs shouldn't be playing games like 5E. Cause you can't play in the AD&D tradition of 10-12 players that way without the game being nothing but grind.