My iPad shut off unexpectedly and won’t turn on

My IPad 9th generated is around 2-3 years old now and it jut suddenly shut down while I was playing a powerful game on Roblox. I was playing a game when the iPad started slowing down and lagging, I thought nothing of it because it always did that. After a few minutes the iPad just shut up or crashed, it started to boot back up and show the Apple logo but once it reached the lock screen it turned off again. The battery was at around 70%-80% when it turned off. Now it hasn’t been turning on, showing signs of life, showing up on a computer, showing the Apple logo, or going into recovery/DFU mode. I tried everything such as holding down the power button + home button, connecting it to a computer, charging it for over 20 hours, etc. It has never experienced any physical damage and never had any boot issues until now. What happened to it? Is it fixable? Does it need to be repaired? Is it a software or hardware issues? I just want to know what happened, what caused it, and if I should just buy a new iPad.