Why can't I delete apps on my IPad?

See: Delete apps from iPad - Apple Support

If there is no option to delete any app, the usual reason is a restriction on deleting. See instructions in Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support

If you are experiencing difficulties with removing Apps from your iPad, you need to check your ScreenTime restrictions:

Settings > Screen Time > Content & Privacy Restrictions > iTunes & App Store Purchases > Deleting Apps - ensure that this permission is set to Allow

How to delete apps on your iPhone, iPad and iPod touch – Apple Support

Please check: Settings - Screen Time - Content & Privacy Restrictions - iTunes & App Store Purchases - Deleting Apps = Allow.