Euromaidan succeeded because it also had massive support and influence from the western powers and from the western(mostly US) itelligence agencies to make the pro-Russian regime change happen.
Similar to the fall of the Berlin wall and the fall of communism in Eastern Europe, it was a decades long effort from the US itelligence agencies, they didn't just sit around and wait for the local population to revolt.
People ignore how much external interference these revolutions get in order to make regime changes happen.
If the public knew everything the CIA was doing, they would be not very good at their job. Stuff like this is usually declassified only 50+ years later or sometimes never. So please, let's not use the "I've only seen Russian agents in the streets but not CIA" as some sort of argument since that insults everyone's intelligence.