Trump lost fairly, so storming the capitol is treason. Yanukovich didn't win fairly, so removing him is warranted. The answer flips because the situations are the opposite.
The people who stormed the Capitol didn't think Trump lost fairly. So the real difference is whether they succeeded. Had the Capitol protesters succeeded, they would have made the media feed people like you and I their narrative and make sure we saw them as freedom fighters.
I'm sure you'll disagree with the above, so here's a thought experiment. What would the Euromaidan protesters be called if they had lost?
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).