"As long as it is done peacefully and with willingness to engage in open dialogue. "

No, it absolutely does not.

You have absolutely not right to suppress other people with your ideology for anything other than a moment.

"Without it, the democracy crumbles"

This is completely false.

There is no such thing as 'peaceful' closure of public transit, it's only authoritarian, frankly.

There are exactly 0 examples of 'democracy crumbling' because protestors were not able to stop public transit and public roads.

In very certain terms - you don't have the right to close public spaces, to stop public activity with your political ideology.

It's completely illegal if 1 of you do it, it doesn't make it legal if 1000 of you do it, though you might get away with just a fine or whatever if you 'take it down' soon enough.

It's helpful to think of a cause that you don't support, or are perhaps against, even think of as 'immoral' and consider how you'd react if they shut your office down every few days.