The BPO industry has always been rather fragmented. One problem has always been how to capture the correct data to come up with estimated revenue numbers for the industry as a whole. Market intelligence firms are usually looking at Annual Contract values above 5 Million (some firms will include lower ACV's of 3 Million US-$).
As such the decline in Annual Revenue numbers is rather "top heavy"...it is geared towards bigger contract values.
What is not captured in annual revenue numbers is the shift away from traditional BPO providers to a more distributed workforce model.
A new breed of providers has emerged which cater specifically to organizations who have demand spikes for services followed by a significant decline.
In the past conventional BPO providers were tasked to absorb those demand surges and had to staff accordingly. Not any longer.
There are now specialized providers who offer "On Demand" (aka Access Contractors) employees to handle those demand spikes. The model is highly attractive to any sales heavy organization (etailers) which has to absorb strong seasonal changes in sales volume. (either promotional or seasonal driven)
The distributed workforce model has always been plagued by a rather high error rate. But that has been changing. Tasks have been further reduced into missions. A mission specific employee is tasked with such a small subset or responsibilities that training and subsequent error rate are both minimal.
Making an employee mission specific instead of a more general trained employee in a BPO environment has allowed the distributed workforce model to gain rapid speed.
There are companies in India which have created significant workforce's of on demand workers which can be marshaled into action within a few minutes. (the biggest providers are in the 1000's of workers or "Access Contractors").
Access Contractors claim that there error rate is about even to the error rate of conventional BPO providers.
The lure of using an Access Contractor is in the associated savings. Savings can be as high as 70 % (!) vis a vis a conventional BPO provider.
Given the realized savings it is easy to foresee continued revenue drain for the established BPO providers. It is one more thing to worry about, besides the emergence of cloud services and AI.