My sonos network doesn't work any more

Sounds like, at least potentially, you have multiple issues going on, exacerbated by resetting each device. Let’s try to deal with one at a time, and get through them to get to your system working. 

Open up your Sonos S2 controller. At least one Sonos device is showing up? Unplug all other Sonos devices from power. Connect that one (and only one) device to your router with an Ethernet cable. Give the system a few minutes to recognize the new connection, and switch over to SonosNet. Then plug back  in the next Sonos device. It should find the SonosNet network (well, except if it is a Roam, Move, or Era speaker, but you didn’t say you had any of those, just speakers you’ve had for ten years, long before these were made), and connect. If it doesn’t, go ahead and factory reset it, then use the ‘add a device’ process in the S2 controller to add it to the existing system. Do this process for each of the rest of your speakers.

Once all speakers are reconnected, you can go in to the Sonos controller, and set the network information, making sure it matched with the Sonos Network Requirements FAQ.  You can then remove the Ethernet cable from the one device you wired if you want (although I would leave it wired, and skip this step). 

Once all of this is done, let us know what other issues you’re running in to.

Just as a note for others, as I suspect you’ve found out, doing a factory reset erases all information, including streaming companies and playlists from the Sonos speakers. Since you’re (hopefully) starting with a device that hasn’t been reset, each speaker will populate copies of that data from that un-reset device. If you’ve reset all of them, though, you will have erased all that data, and need to re-enter it.