Just to clarify, Apple has not abandoned Time Machine......which is software on your Mac that used to back up the Mac to another device.
Apple did discontinue the Time Capsule......which was hardware........ a WiFi router with a built in hard drive that could be used to store backups made using Time Machine on your Mac.
There are no other products offered by other manufacturers that combine both a WiFi router and an hard drive in one single package.
If you can accept two separate devices, check out the Synology router, which does fully support Time Machine backups to a USB drive attached to the router.
Synology RT2600ac │ AC2600 high-speed Wi-Fi router ...
Some of the upper end Asus models will support Time Machine backups this way as well.
If you already have a WiFi router, take a look at the Network Attached Storage (NAS) solutions available from Synology, which do offer Time Machine support.