First of all, Apple's authorization control of accessories is very strict, and only accessories certified by MFi can be used and sold on Apple products. The MFi certification process is strict, and a lot of R&D expenses need to be invested to ensure that the design, production and testing meet the requirements of Apple certification. Therefore, only accessories manufacturers that meet Apple standards can obtain MFi certification.
Secondly, Type-c and Lightning are two different interfaces, and the data transmission and charging protocols are also different. Although there are some adapters from Type-c to Lightning on the market, these adapters may not be certified by MFi, so they cannot be used on Apple products.
In addition, market demand is also an important factor affecting the sales of Type-c to Lightning adapters. Because the Lightning interface can no longer meet Apple's demand for professional productivity, Apple has gradually eliminated this interface and switched to the Type-c interface. This has also led to a decrease in the market demand for C-to-Lightning adapters.
Finally, considering the factors such as cost and certification fee, some manufacturers may be reluctant to invest a lot of money to produce and sell Type-c to Lightning adapters. This may be one of the reasons why big-name manufacturers like UGREEN don't produce this adapter.
To sum up, there are generally no MFi-certified Type-c (female) to Lightning (male) adapters in the market due to strict requirements for MFi certification, reduced market demand, production costs and other factors.