He cited four factors that would make Singapore harder to govern, regardless of which party is in power.

These are:
“First, the ability of governments to control information will continue to erode, despite sometimes frantic and illogical attempts to stem it.”
“Second, it will be increasingly difficult to hold the political centre together in the midst of polarising extremes.”
“Third, diminution in the stature of political leadership will encourage the rise of so-called „non-constructive“ politics.”
“Fourth, maintaining an ethos of egalitarianism in an increasingly unequal society will require more than just political oratory.”

On the last point, Mr Ho added: “The gulf between rich and poor Singaporeans, not only in terms of wealth but also in terms of values, is probably more than ever before, and is continuing to widen.”

My take on this is that what makes Singapore less governable is also what might cause the PAP to lose power: the growing gap between rich and poor.