Macbook Pro (15-inch, 2018) struggling to turn on.

Hello, in recent months my Macbook Pro (15-inch, 2018) running macOS Big Sur is struggling to boot up after shutdown. In the past my Macbook would start upon opening the lid but now it just refuses to start up. I'll press down on the track and it still will not boot up. When I finally press or press and hold the power button, the Macbook will start to produce power as signified by anything connected to my USB-C hub beginning to charge but a black screen on the Macbook. Sometimes the Macbook doesn't load macOS Big Sur all until I just begin pressing random buttons on keyboard and in other instances the Macbook will eventually boot up on it's own accord. Can anyone please tell me what's causing this issue and how do I go about fixing it.