To be clear, Yanukovych was fairly elected in 2010 and there are no claims that this was somehow rigged or undemocratic (https://en.wikipedia.org/wiki/2010_Ukrainian_presidential_el...).

The protests started when he switched his stance on getting closer to EU. The protesters got him out and had a new election. How can you compare that to not accepting an election result?

Edit: To answer your question: if the Euromaidan protest didn't succeed, it was just a protest like it was now. They would have had another election a bit later, possibly pissing off Russia again (In 2004 Russia poisoned a pro-EU candidate).