That is the popular ideology that was used to justify most of history's worst atrocities.

Piet Hein, who coordinated the Danish Resistance (which was, arguably, the will of the Danish people, though even today the Dansk Folkeparti has seats in parliament) satirized the situation in this grook, entitled Majority Rule, in 01969:

His party was the Brotherhood of Brothers,

and there were more of them than of the others.

That is, they constituted that minority,

which formed the greater part of the majority.

Within the party, he was of the faction,

that was supported by the greater fraction.

And in each group, within each group, he sought

the group that could command the most support.

The final group had finally elected,

a triumvirate whom they all respected.

Now of these three, two had the final word,

because the two could overrule the third.

One of these two was relatively weak,

so one alone stood at the final peak.

He was: THE GREATER NUMBER of the pair

which formed the most part of the three that were

elected by the most of those whose boast

it was to represent the most of most

of most of most of the entire state —

or of the most of it at any rate.

He never gave himself a moment's slumber

but sought the welfare of the greatest number.

And all the people, everywhere they went,

knew to their cost exactly what it meant

to be dictated to by the majority.

But that meant nothing, — they were the minority.

⁂

The idea of limited government I described, which is fundamental to liberalism, comes essentially from Locke's Two Treatises of Government in 01689. Rousseau responded in 01762 with the idea you so ably summarize, the absolute sovereignty of the "will of the people", in The Social Contract, calling it "the general will": https://www.marxists.org/reference/subject/economics/roussea.... Rousseau already recognized the failure mode Hein skewers in the grook above, but he hoped to avoid the formation of political parties.

Condorcet's paradox showed that the will of the people was incoherent in 01785: https://en.wikipedia.org/wiki/Condorcet_paradox

In 01793, the will of the people decreed that the streets of Paris should run red with the blood of France's greatest and most honorable; Robespierre the Incorruptible carried out this Terror justified by Rousseau: https://en.wikipedia.org/wiki/The_Terror

In 01850, the will of the people established the Fugitive Slave Act, requiring all government officials throughout the US to assist kidnappers of fugitive slaves, sending them back to the most abominable system of slavery humanity had ever known, a system itself established by the will of the people of the Southern States: https://en.wikipedia.org/wiki/Fugitive_Slave_Act_of_1850. A few short years later, the will of the people of the US decreed that those people should start killing one another en masse, ending with about a million dead, but four million delivered out of bondage.

In 01918, the will of the people created the Solovki prison camp, which grew into GULAG over the next decades, through which 18 million people would be forced to labor for the will of the people; some 1.6 million died: https://en.wikipedia.org/wiki/%D0%93%D0%A3%D0%9B%D0%90%D0%93

In 01933, the will of the German people passed the Enabling Act, making Adolf Hitler dictator; before the war was out, the will of the people would murder ten million people in concentration camps: https://en.wikipedia.org/wiki/Enabling_Act_of_1933

In 01951, Kenneth Arrow published his Impossibility Theorem, showing that the idea of the "will of the people" was incoherent in a far more comprehensive sense than Condorcet had ever imagined: https://en.wikipedia.org/wiki/Arrow's_impossibility_theorem

In 01958 the will of the Chinese people manifested in the Great Leap Forward, which Mao justified by explicit appeals to Rousseau's ideals. The largest famine in human history, or possibly the second largest, was the result. https://en.wikipedia.org/wiki/Great_Leap_Forward

In 01974 Hayek was awarded the Nobel Memorial Prize in Economic Sciences for explaining how voters and government institutions are unavoidably laboring in ignorance of much of the information needed to make the decisions that are optimal for the general welfare, while the price system can approximate those optimal decisions more closely: https://en.wikipedia.org/wiki/The_Use_of_Knowledge_in_Societ...

⁂

The list of atrocities justified by the will of the people goes on and on: the Killing Fields, the Holodomor, the US system of mass incarceration, the Tutsi genocide, the Congolese civil war, the North Korean dictatorship, and on and on. You might protest that these atrocities were not in fact popular, that dictators were lying about what the people wanted; but by and large you would be incorrect. In other cases the policy of establishing limitless state power was popular, but the atrocities in which it inevitably culminated were not.

That is the policy Rousseau advocated, and it is the policy you are advocating in your comment. In 01762 the idea that the will of the people could never err and would always promote the general welfare was an understandable error, but today we have ample evidence, evidence written in rivers of blood, that shows otherwise. Liberalism—giving individual people great freedom to dissent from the will of the people—works less badly. I know it's not very inspiring to chant "Our system works less badly!" but that's the best we can do so far.

This does not necessarily imply "shrinking government", but it does imply strong limits on the powers in the hands of that government.