you suggest a system where citizens could vote for no confidence in the gov at any time , so to dismantle it.

Today's systems allow a vote of no confidence only to the elected represenetives. a national refarandum is usually required by law for some decisions (e.g. appoint some positions in the US) or to assure stable governence (e.g. brexit). a vote of no confidence does not hold to these critiria. In today's democratic systems the closest parallel to what you are talking about is instsblity forcing the gov to go to early elections, or cause defectors in the parlament coallition to vote for no confidence. Both are cqused duo to public pressure, but not by the direct vote of the people.

let's assume now we create such a system. something must trigger a vote, what is it? is there a monthly vote? can a patition like system allow for a vote if enough people request one? what are the logistics of the votr process? it should be at least as secure as the elections. That costs a lot of money, and adds a whole lot of overhead. The vote should also be as fair as elections, most countries, unlike thr US, consider election days as national holidays and close most buissneses. That takes a toll on the economy if done too many times.

Now consider you live in a highly polorized vountry where public opinion swings radically from side to side. a system suh as this will surely distablise the gov, which will change on a bi-monthly rate. This can cause the gov to cease functioning all together, imcluding military budgeting. With a weakened army the country may fall to out side forces, or worse fall to a military coup, which may be dictatorial in nature - destroying democracy in tje process.

tl;dr: Gov sytems are hard to create

Moving as many things to the city, and even community level is great. On the other hand natonal level consideration like the planning and construction of new trade routes (e.g. the panama canal, transcontinental railway) of the future (e.g. astroid mining operations) will always stay in the national and even international level.

as a group grows, the issues at hand become more complex, and then the standard citizen no longer has the time to both work and inform himself on the issues of the day to also participate in day-to-day politics in any meaningful way. Just like anything else, over a certain size specialization is required.

eh... so long as lemmy does not allow server maintainers a means of monitezation I don't see how lemmy could support growing over a certain size... sorry.