The M5S, at its inception, was founded on the idea that elected representatives should be little more than spokespersons for the voters, and a continuous consultation of the electorate was necessary to make political decisions. It's true that the system didn't work well because it only referred to a small number of voters, a minimal part of the members of the movement, around 100,000 compared to the millions of voters. In practice, the consultation platform was set aside, along with most of the naive and innovative principles that were considered the foundations of a TRUE democracy, a new political model proposed by Grillo and enthusiastically accepted by many, though criticized by a few political experts.
However, the question remains as to whether it would indeed be possible to continually consult the voters and whether this would lead to a true democracy, based on the actual popular will and not on a very limited number of elected individuals who promise many things during the election campaign only to disregard them once elected. It is believed that online platforms, which are an integral part of our daily lives, could be used for an easy and quick consultation of voters, not only from one's own party, as attempted by the M5S, but from all voters. It proposes, therefore, a kind of continuous referendum.
In our constitutional system, the referendum is defined as an institute of direct democracy. However, it is provided for as an exceptional measure: it is only abrogative, excluded for budget, international treaties, amnesties. In practice, it is used for general ethical (divorce, abortion, etc.) or institutional issues and has always faced significant participation and practical application problems. No one with even minimal political knowledge seriously thinks of governing with continuous referendums.
We could first note that continuous consultation is already carried out by numerous surveys that provide us with the moods and orientations of the electorate every day, in real-time, as they say. They are more reliable than any online referendums: in fact, only a small portion of voters, those more motivated or passionate, would respond to them, not necessarily representing the entire electorate (the famous silent majority). The "sampling of the statistical universe" (as it is called) is essential to get an idea of real opinions. If you invite everyone to vote, only some will do so, and you will get a distorted idea of the whole. For example, on many online discussion forums, you might get the impression that fascists and communists (real ones) are important forces, while in reality, they are politically insignificant minorities that cannot even elect a parliamentarian. Reliable surveys always need to be conducted on samples, which is a difficult task requiring qualified individuals.
Measuring approval corresponds to assessing the measures taken, albeit less clearly. If I voted for a certain party before and no longer do, it means I do not approve of the measures it has taken, even if it's not clear which ones.
However, this is a secondary issue. What really matters is that if people vote continually, they judge events based on immediate impressions, while politics requires long periods to produce effects on which voters can then express themselves. A principle proposed by every expert is that one should not govern taking into account the moods, the plethora of surveys reflecting the changing impressions of people because, in politics, it takes time, often a lot of time, to see results.
It is clear to everyone that stability is very important, and democracy is fragile and inefficient if stable governments cannot be established (see Merkel for 16 years). The principle of every representative democracy, the only one actually existing and, I would say, possible after the failures of every other direct form, is that voters periodically judge the work of leaders, and if they consider it positive, they re-elect them; otherwise, they elect others.
Since ancient times, Plato noted that one of the flaws of democracy is demagoguery, i.e., promising things that cannot then be kept. For this reason, democracy works in evolved countries where people can distinguish the possible from the impossible. Realistically, everyone promises more than they can keep: some may exceed, and some may stay within limits. Politics is the art of doing what is possible, not doing what would be good but is not possible. It is not possible, for example, to lower taxes and increase services, even if this is often promised during an election campaign.
However, a politician should prefer not to do absurd things rather than keep promises. On the other hand, if a politician does absurd things to keep promises, they will not be re-elected, but if they do reasonable things, even if in contrast to promises, they may be re-elected. In short, promises don't matter; what's important is DOING GOOD THINGS.