Microsoft Store failing to install/update everything

[Windows 11]

TL;DR - Microsoft Store is in some crazy state where it will download and attempt to install items, but will fail every time with the same error. This includes items it's already installed, basic Microsoft apps (e.g., the "Get Help" app), and new apps I try and install.The error code is the same for each one: 0x80070490Screenshot of the store trying to update:

Continue reading...