Certainly efficient, in making bright light using few components
Certainly sparing the earth much mining for minerals
Certainly they can last long, at least to 20,000 hours at low price, as shown by mentioned small manufacturers, when major manufacturers don't control the markets.
Certainly sustainable, in being easily locally made generic patent-free bulbs, without much transport of parts or product, and without needing recycling.
Incandescents don't burn coal and they don't give out CO2 or other emissions.
Power plants might - and might not.
If there is a Problem - deal with the Problem.
Power plant emissions are decreasing on present policies, both from alternative source use and in directly being reduced and treated in various ways.
The main evening-night time use of incandescent bulbs only consume small amounts of off-peak surplus capacity electricity anyway, as referenced.
Even then, base loading coal power plant minimum night cycle levels means that basically the same coal is burned, regardless of light bulb choice.
Incandescent light bulbs:
A pointless very visual feel-good target for an agenda driven ban seeking to ensure that the world loses the simplest cheapest product it ever had to produce light from electricity,
an aesthetically pleasing versatile invention, whose doom would arise not from being unpopular, but from being popular, through the stupidity that passes for global governance.
How Regulations are Wrongly Justified
14 points, referenced:
Includes why the overall society savings aren't there, and even if they were, why alternative policies are better, including alternative policies that target light bulbs.