2010 Mitsubishi Outlander has less power?

I have a 2010 Outlander GT and when I first got it, I could chirp the wheel in 2nd gear let alone first. In first gear I could raise lots of smoke. The tires were brand new too. Now after 3 years. I did a full throttle acceleration from 0mph and it didnt even chirp first. The tires are the same but much more tread has gone. I tried to brake boost a day later and nothing. It also feels like it has to downshift more to get up a hill I go on everyday thats pretty steep. Has it lost power?