Having just one gear on the front sounds like it’s just a matter of taking off the other junk, but with that setup, SRAM said they were constantly dropping their chain. To fix this, they developed some crazy teeth that grip the chain like a Great White with anger/hunger issues, using different shaped male and female links with stepped profiles.
To cope with only one chainring up front, SRAM uses a super wide cassette in the back that has an enormous granny gear to handle the climbs. You can also swap out the front chainrings to taste as well. According to one of the SRAM guys, their office hasn’t missed that derailleur one bit.