I dealt with this exact issue during my remodel. The biggest mistake I made at first was trying to rush it. Light scoring, warm water with a remover solution, and giving it enough time to penetrate made a huge difference. When it became clear the layers were too stubborn, I looked into professional wallpaper removal Arlington
https://bestwallpaperinstaller.com/locations/wallpaper-installer-seattle/wallpaper-installation-arlington/ services to avoid damaging the drywall further.
They handled the adhesive residue properly and skim-coated the surface so it was perfectly smooth for finishing. If you plan to repaint or reinstall wallpaper, careful removal is absolutely worth the effort.