"increased discontent" is a perfectly correct and usable phrase in written English.
You can use it to describe a situation in which the level of dissatisfaction or unhappiness has increased. For example, "The citizens of the country have been expressing increased discontent with the government's handling of the pandemic."
The cost of the war and the large indemnity paid under terms of the peace treaty further increased discontent.
An economic slump in the 1870s brought increased discontent among the labour unions, one result of which was a demand for the exclusion of Chinese labourers, who worked for lower rates of pay than did "whites".
The latter include increased discontent about racial profiling,7 its high implementation cost, minimal oversight and support from ICE, and accusations that the agreements are used as political tools that interfere with protecting and serving communities (Immigration Policy Center, April 2, 2010).
Its increasingly frequent delays and smaller more uncomfortable airplanes -- have resulted in increased discontent among the airlines bread and butter business travelers -- including "1-K" travelers like me.
"All it did was to increase discontent among nurses.
The problems at Network Rail have contributed to increasing discontent among passengers.
This may suit some but research shows [pdf] that poorer pay and conditions often increase discontent and disengagement.
Increasing discontent among the Mizo, however, led to a declaration of independence by the Mizo National Front in 1966.
Increasing discontent reached a climax in a conspiracy of the princes led by Anno, archbishop of Cologne, in April 1062.
This comes despite an exclusive poll in today's Observer which shows increasing discontent with Blair, suggesting that he may be a major election liability rather than asset.
The cable says that the nuclear test had been done at a time when the Indian government was tackling an economic slowdown, increasing discontent and rising political unrest.
