Launchpad is not available in macOS 26 Tahoe. Instead, Apple has replaced it with a Spotlight-based application library similar to that on iOS. By default, the Apps app replaced the Launchpad app in your Dock (if it was there). macOS organizes the apps, you cannot manually sort them. To have Apple consider your feedback on this issue, submit it here:
Feedback - macOS - Apple
A possible workaround might be a 3rd party app, such as AppGridLauncher app (Mac App Store link) or https://www.launchie.app/.