Tape on buttons necessary? (Power button, volume buttons)

I was having issues with the power button. It felt like a loose contact getting worse over the last weeks. So i decided to get a new button for like 4€ and to open my OnePlus 5T:

I saw that there is tape between the power button (connected to the main board) and the plastic button on the (at that point removed) phone cover. That tape looked really perforated and could easily be the cause of issue. Since most of the assembly tutorials/videos don’t attach any tape after installing the button, I decided to simply remove the tape and continue to use the original power button.

Has that been a good idea? What’s the use of that tape on the button?