I have had many chinese phones (Huawie, Oppo, Xiaomi) over the years and the things they choose to kill in the background is odd. Web browsers and almoat any kind of banking app will be killed in minutes if not seconds. VLC... Depends on the day could be minutes or days. No idea why that one.

Hard to tell if it something I am doing or not. I will say with all these phones and everything google turned off I typically get 3-4 days per charge but that really depends on what your usage is.