Hmmm...
Macro coils generally have a diameter over 2mm-2.5mm. People typically use them for high-powered vapes and hotter coils because the wicking demands are very high and it is beneficial to be able to have more juice running to the coil at any given time. For instance, if I want to run a .2 dual 22g at 100w, then I'm gonna make the diameter a minimum of 3mm because if I don't, those coils are going to go through juice so quickly that I will get dry hits.
Micro coils, which are generally 2mm or smaller, work better for cooler or even warm coils that don't require as much wick. The smaller diameter allows the coil to heat up more evenly and quickly. This is especially helpful on mech mods.
"Micro" also more traditionally refers to what is also called a contact coil, which is exactly what it sounds like... ...it's a coil where all of the wraps are touching. This usage originated in a time when there was still a large portion of vapers building coils with the wraps spaced apart from one another. Nowadays, when someone mentions a micro coil, they're talking about the first definition, not this one.
Now, high-resistance coils. Not everyone who vapes cares about clouds at all. Some people like a cool, single-coil vape. Depending on your preferences and the amount of airflow on your device, a 1+ ohm coil may be your ticket to flavor town. Tank system users tend to be the ones who like these builds the most. It's all about the surface area. A large, high resistance single coil wrapped with thinner wire (26g and down) can generate a lot of flavor and a satisfying amount of vapor with less power and heat, which is conducive to better performance in a tank system, where airflow and wicking capabilities are more limited.
I'm not sure why you think that dual coils produce little vapor. That is only true if they aren't getting adequate power. Everything about them is geared towards warmer, denser, more flavorful vapes... ...especially in RDA's, which are the kings of airflow and chamber space. A dual coil has half the resistance of a single coil with the same wrap count, which means it pulls double the power on an unregulated device. That is to say that they need double the power, though. More metal requires more power to heat up. This also means that the surface area is doubled. In terms of vapor production, duals will typically outperform their single counterparts by a wide margin because they have that much more surface area. A larger surface vaporizes more juice at any given point in time.