What are the limitations in adoptions of GTF (Geared Turbofan) technology?
The factors that are relevant here are:


Increasing the bypass ratio is very desirable in order to improve the efficiency of the engine, and for the same amount of thrust, this means increasing the fan diameter.
In order to keep the fan mostly subsonic, the fan rotational speed has to decrease with increasing fan diameters. Supersonic fan blade tips are possible and in use, but you lose efficiency and increase noise, so it's desirable to limit this to the outermost area.
For the same efficiency, a low-speed turbine requires more stages and therefore more weight compared to a high-speed turbine. Compare the PW1100G's 3-stage LPT (geared) with LEAP-1A's 7-stage LPT (not geared).
The only way to decouple the rotational speed of the LPT from the rotational speed of the fan is by using a gearbox.


In the long run, this is therefore a question of whether the gearbox is heavier than a slower-turning LPT and whether a possible increase in maintenance costs due to the gearbox is acceptable for the given gain in efficiency or reduction in engine weight. With further increases in engine bypass ratios, the gearbox becomes increasingly attractive. 

In the short run, this is also a question of whether a company wants to risk developing a completely new component, with potential problems before and after entry into service. Additionally, with a given amount of money and manpower to develop a new engine, management will ask: Where are the engineering hours going to make a bigger difference, in improved fan, compressor, turbine and combution chamber designs/materials/... or in a gearbox design.

So while, for example, Rolls-Royce does not manufacture a geared turbofan right now, their "UltraFan" research engine project does include a gearbox. I think it's safe to say that it is only a matter of time until most commercial turbofans will include a gearbox.