Well, this was the solution. Un-install and re-install XBox and Gaming Services. Why, the last resort was to check the Event Viewer and that pointed to this error.
Faulting application name: WinStore.App.exe, version: 0.0.0.0, time stamp: 0x6ab5a3b1
Faulting module name: gameplatformservices.dll_unloaded, version: 10.0.26100.8569, time stamp: 0x86ae99ec
Exception code: 0xc0000005.... blah blah blah
So I then search Gemini for the failing module name above. Which pointed me to a YTude video which instruction to resolve the problem. Steps: un-install Xbox, reboot, install Xbox, reboot, install Gaming Services, reboot. Open Store app, result: no crash. Clean Event Viewer.
Edit: I forgot to mention the other problem with the store app was that it blocked me from pausing the updates. Fixed:
Fix via Registry Permissions1. Press the Windows Key + R, type regedit, and press Enter to open the Registry Editor. (Always back up your registry before making changes.)2. Go to this path:HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\InstallService3. Right-click InstallService, choose Permissions, select Users, and check the box to allow Full Control.4. Go to the subkey:HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\InstallService\State5. Right-click State, choose Permissions, select Users, and check Full Control.6. Close Registry Editor and reopen the Microsoft Store to pause updates normally
All this started after 26H2. If not. Microsoft secretly broke my Store app underneath me through their wretched updates.