A capacitive dropper

In this case 10uF is much to big and above a good acceptable little capacitor dropper for boostrap supplies in e.g. SMPS. I think below and max 1uF is acceptable for special situations, but above its not and you better use a transformer. Cuz even it does not waste power in your network (or not much), it does waste power over the long line to the power station, thats why power provider do not like that way of voltage dropper. 1Apeak is transfered back and forth again and again without transformation into useful form of energy. You just store it in the cap and move it along the 10of kilometer powerline to store it again. So the waste of energy happens outside your home network and the provider has to pay for! 😜

Thank you @hurz for commenting and providing more information. Undeniably, capacitive dropers are wasting power in the long power lines. The thing is that a capacitive dropper is the simplest and cheapest and most reliable form of 'transformer' that i can think of. But with some drawbacks like having high electric potential referenced to ground at the output and the power loss you've mentioned, i can see why capacitive droppers are not used everywhere.

You say 'most reliable form of transformer' and this is misleading. Its some how a transformation but i wont use the word transformer. Its not a magnetic field transformer which does a galvanic separation. Thats why a capacitor is a bad way to use it for higher power them 50mW or so. Because of missing galvanic separation its even dangerous. Your example uses 10uF and is good for 10W or more, and is far above any secure current limits.