Wifi wont connect self assigned IP address

A self-assigned IP is a sign that the connection with the router failed, and the router was unable to give an IP address to the computer. That doesn’t mean that there is anything wrong on the computer. The issue can easily be the router.

Restarting the router (a soft reset with a button if present, or even a hard reset with disconnected power for half a minute) often fixes such issues, but if it happens frequently, then one should investigate a cause for the behavior. It could be the provider or the router itself.

“Wifi has the self-assigned IP address fe80::1cd4:b606:23b6:892a

that is an IPv6 address. Most home Routers are using IPv4 for their ordinary connections.

The Mac is perfectly capable of doing everything over IPv6, but it is unusual to be using that for data transport on your Home network. Normally, IPv6 is se to "Link-local only", and is only used locally for Bonjour service discovery (automatically finding Printers and Servers).

Check to be sure you have IPv4 set to: Using DHCP (or manually if you have decided to manually assign addresses)

You must be aware of etrecheck this is created by respected member of the forum , just to view what is running in the Mac , if you please post the results , see this link https://etrecheck.com/

Both the 2.4 GHz and 5GHz re set to Automatic (smart wireless) channel selection

Great. Then reset or cycle the power on your Router, and see if it selects a channel that will stay connected and give you good signal-to-noise and good transmit rate.

You may be too far away from your Router, or have equipment that is generating interference positioned too close to your Router or too close to your computer.

One unusual problem that sometimes occurs is positioning the computer right on top of the Router. In this case, the signal can be "too loud" and overwhelms the Receivers. Best operation is from a few feet away.

If you are using a computer with USB-C devices attached (MacBook pro 2016 or 2017 models), that has its own set of problems. Please post back for more information if that applies.

the fact that there is no router listed that this could be the problem?

No, I think that is a symptom. I think the problem is that your neighborhood is too crowded, and there is too much competition from your neighbors.

You have very good signal RAW strength. But your Noise level is WAY too high! That number should be down at -80 to -99. so signal-to-noise in this snapshot not very good.

The rest of the parameters look great. You seem to be successfully using multiple antennas and achieving good nominal Transmit rate. You don't appear to have a broken antenna in your MacBook.

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One thing to try is to verify that your Router is set to "Automatic" channel selection. Then when your Router powers up, it will "sniff" the airwaves and move channels to the the least-busy channel at that moment. That will give you good reception for a while, at least until one of your neighbors makes a change. ( This is why every debugging procedure starts with "Cycle the power on your Router.")

it is a configuration option inside the Router.

Most Routers are accessed by entering the Router address in the search bar in a Browser:

http://192.168.0.1

then logging in and changing Router settings. The Router manual may be helpful for this.

Some experiences about network , the server was down and thought of deleting the network interface plist that you even tried , suddenly stopped as all network settings are perfect even the Mac is not joining .

Take your Mac to a friends place and try to join the network , if a problems comes it means Mac is corrupted and if its working fine it means you are having weak signals , blue tooth interference , or blockage of wifi signals as what the member Grant Bennet is trying to explain .

Some times a new user account is created just for testing see this article How to test an issue in another user account on your Mac - Apple Support

And then try to join the network , I would still had a thought of reinstalling the os , as you did a mistake of removing network plist files , these are not be deleted , its always better to install os

The network plist files , that are deleted by op into the trash , then again put back in the same location is to be avoided , some articles op can read Recommended settings for Wi-Fi routers and access points - Apple Support

Check for Wi-Fi issues using your Mac - Apple Support

How to troubleshoot Wi-Fi connectivity - Apple Support

But WPA2 personal settings is must , it should not be none .

Do you have any computer equipment (including displays) within a few feet of the Router?

This can sometimes cause interference.

Are you using a computer with USB-C ports ? (MacBook pro 2016 or 2017 models).

Is your home built with solid masonry construction? brick interior walls, second-story cement floors, many-feet-thick interior chimneys, or Plaster-over-wire lath?

I have tried all the usual solutions including deleting files:

Com.apple.airport.preferences.plist

Com.apple.alf.plist

Com.apple.network.identification.plist

NetworkInterfaces.plist

These files are not be deleted , you can erase the hard drive and reinstall the os see this article macOS Sierra: Erase and reinstall macOS