Do you have screen time enabled?.
Launch the iOS Watch app on your iPhone.
Tap My Watch in the bottom-left corner of the screen.
Scroll down to the "Installed on Apple Watch" list and tap the app that you want to uninstall.
Toggle the switch next to Show App on Apple Watch to the grey OFF position.
How to Delete Apple Watch Apps From Your Watch.
Press the Digital Crown on your Apple Watch to bring up the App View.
If you're using List View, swipe left across the app you want to remove, then tap the red trash button. If you're using Grid View, tap and hold to activate jiggle mode, then tap the X in the top-left corner of the app you want to remove.
Tap Delete App to confirm.