What controls the frequency of tropical cyclones?
Here’s an interesting review paper from 2021 on one aspect of tropical cyclone research, by a cast of luminaries in the field – Tropical Cyclone Frequency by Adam Sobel and co-authors.
Plain language summaries are a great idea and this paper has one:
In this paper, the authors review the state of the science regarding what is known about tropical cyclone frequency. The state of the science is not great. There are around 80 tropical cyclones in a typical year, and we do not know why it is this number and not a much larger or smaller one.
We also do not know much about whether this number should increase or decrease as the planet warms – thus far, it has not done much of either on the global scale, though there are larger changes in some particular regions.
No existing theory predicts tropical cyclone frequency.
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The Science of Doom 
No prediction of tropical storms? Wasn’t hard to find a decent set of conditions.
Global weather models, especially the ECMWF, GFS, and UKMET are the primary tool for predicting Tropical Cyclones they assess the development of the disturbance itself and to examine environmental factors that contribute to the Tropical storm’s birth.
For these disturbances to grow into a tropical cyclone, the following environmental conditions must be in place:
Warm ocean waters (at least 80°F/27°C).
An unstable atmosphere is driven by differences in temperature, where temperature decreases with height.
Moist air near the mid-level of the atmosphere.
Must be at least 200 miles (with rare exceptions) north or south of the equator for it to spin (due to the Coriolis effect).
Little change in wind speed or direction with height (known as low vertical wind shear).