I use Zeek at home with the Security Onion distribution. It's an Intrusion Detection System distro.
Highly recommend trying it if you want to learn more or monitor your home network.
Zeek is not Snort, or anything like a signature based detection system. It parses the network traffic and writes different type of traffic into easily consumable text files (either text or json). In the Security Onion distro Zeek data is imported into Elasticsearch and accessed using Kibana.
HTTP, SSH, DNS, DHCP, FTP, SNMP, SMTP, X509 certs being used, etc, etc, etc
You can search for specifics or aggregate information in dashboards. Which device is doing what in what time period, or something like the most noisy device, or even figure out devices with scheduled connections (ex. IoT phone home devices).
Security Onion can also store pcap files for the actual data traffic.
It's an awesome way to get to know your local network and to look into details on what is going on. Do you know what your Sonos speaker is doing on your network? What about your internet connected Coffeemaker?
As for Microsoft bringing Zeek into Defender, I'm not sure. They don't have anything even close to competing with Zeek and Microsoft seems to actually commit to open source these days. Really hope they don't ruin Zeek. It's awesome.