iphone 17 pro battery life is not as expected

hi all, i recently purchased an iphone 17 pro after seeing about the large battery size and the around 30 hours of video playback. however, my phone seems to be draining battery faster than i would expect it to, for example after only around half an hour of watching tiktok i lost around 7% battery, and after watching a video on youtube for around 20 minutes, i have lost 2% already, is this normal for the 17 pro?? im worried that my battery may be defective or something like that, it says my battery life is on 100%, this phone is brand new and was only set up 5 days ago.