Context for newbies: Linux refers to network adapters (wifi cards, ethernet cards, etc.) by so called "interfaces". For the longest time, the interface names were assigned based on the type of device and the order in which the system discovered it. So, eth0, eth1, wlan0, and wwan0 are all possible interface names. This, however, can be an issue: "the order in which the system discovered it" is not deterministic, which means hardware can switch interface names across reboots. This can be a real issue for things like servers that rely on interface names staying the same.
The solution to this issue is to assign custom names based on MAC address. The MAC address is hardcoded into the network adaptor, and will not change. (There are other ways to do this as well, such as setting udev rules).
Redhat, however, found this solution too simple and instead devised their own scheme for assigning network interface names. It fails at solving the problem it was created to solve while making it much harder to type and remember interface names.
To disable predictable interface naming and switch back to the old scheme, add net.ifnames=0 and biosdevname=0 to your boot paramets.
The template for this meme is called "stop doing math".
No idea what mactab is, but maybe it solves it for me, but being able to go from interface name back to a rack full of heterogeneous PCI cards and go "yep it should be this port" was a wildly useful feature.
I feel like there should be automatic alias creation for simply interface names though.