The example of Ukraine is complicated, and that situation has become a nightmare With what followed - though in fairness to the Ukrainians, the west could have done a hell of a lot more, and still could.

The Arab Spring turned into The Arab Winter in a wave of repression. Some good has come out of it but the link you have provided says this:

Although the long-term effects of the Arab Spring have yet to be shown, its short-term consequences varied greatly across the Middle East and North Africa. In Tunisia and Egypt, where the existing regimes were ousted and replaced through a process of free and fair election, the revolutions were considered short-term successes.[337][338][339] This interpretation is, however, problematized by the subsequent political turmoil that emerged in Egypt and the autocracy that has formed in Tunisia. Elsewhere, most notably in the monarchies of Morocco and the Persian Gulf, existing regimes co-opted the Arab Spring movement and managed to maintain order without significant social change.[340][341] In other countries, particularly Syria and Libya, the apparent result of Arab Spring protests was a complete societal collapse.[337]

I think the article talks about nonviolent protests - the first two were anything but.

The Slovakian incident worked, because Slovakia has a working representative democracy.

In a deeply flawed, or downright nondemocratic system, like Serbia or Georgia, it's very hard to drive change through nonviolent protests.

It also bears mentioning, that the key issue with protesting, is that it, legally speaking does nothing. Legal representatives are under no obligation to do anything in response to protests.