Chosen Solution
My phone got water damaged but the indicator for it has not turned red (SIM card slot area). The phone responds to touch, the Buttons all work however there isn’t any haptic feedback. When the phone is on, the alarm goes off and I can turn it off by pressing the screen. The charging port also still works.
I suspect that the phone may only need a screen replacement. To confirm this the logic board would need to be removed from the phone to inspect both sides of the board for liquid damage. Also remove the little black foam pieces that are covering around the connectors on the board as water can seep under those areas. There is also a black tape that is removable under the board which I also recommend removing to inspect for signs of liquid damage. If everything looks fine and no signs of water residue on the board then I would go ahead with a screen replacement. Follow up to step 58 of this guide on how to remove the logic board: iPhone 8 Plus Lightning Connector Assembly Replacement iPhone 8 Plus Screen Replacement iPhone 8 Plus Screen Edit: As taptic is gone it is strongly recommended to have the board decontaminated as said by Owen Baker.
The first thing you need to do is decontaminate the logic board with 91% isopropyl alcohol or else your phones lifespan will be decreased. Then you should try replacing the taptic engine. If replacing the Taptic Engine doesn’t work it’s a board level repair.
