On hills of 3-4 minute duration and under 13%, I use big-big ( could be 56x32 or 50 x 36 depending on bike). On extended climbs of at least 8%, I shift to the small ring. My 2x setups have at least 16 or 17 usable gears. To get the same tight gearing on the small cogs and a similar range on a 1x12 isn't possible but it would be close enough with 1x13. I never shift back and forth on the FD as one would in the old days with half step gearing. I use the entire cassette with the big ring and then only shift to the small ring for very steep or very long hills. 2x works for me. 1x13 might convert me.

I can't see SRAM or Shimano getting to 1x13 on road bikes anytime soon. Maybe 2024