I cannot recommend the WeTek Hub at the moment for Android Kodi Krypton usage, due to various video playback issues - that I'm told should be fixed very soon in the next Firmware update. SPMC (Kodi Jarvis) runs much better on it at the moment.
The Infra Red only remote the Hub comes with is also rubbish. You have to buy a seperate Wireless Air mouse remote to use its regular Android touchscreen Apps properly.
Some much easier to use, with the standard Hub remote. Android TV Apps can be directly installed from the inbuilt alternate
Aptoide Store
The FireTV, as you said needs Kodi (or SPMC) to be Sideloaded. You also get a nice Wireless Voice remote.
For Android Apps only - the FireTV will be the easier box to use for non tech savvy users than the Android - WeTek Hub.
If you are a demanding Kodi user, the WeTek Hub running LibreELEC Kodi will be better than any Android Kodi implementation getting about. It very easily Flashes to a microSDHC card, or with some DIY can be installed to faster internal eMMC Flash storage. Kodi does not need a Wireless Air mouse to use.
Networking and HDD connectivity is easier with LibreELEC.
Other options are the Xiaomi Mi Box - that would be the easiest out of all of them to use with its Android TV interface. Simple install Kodi from the inbuilt Playstore. It has about the best Wireless Voice remote getting about.
It all depends on where your primary focus is - Android or LibreELEC Kodi ?
