Not enough information about your setup, so it’s really hard to provide any real assistance. 

Does your network match the data in the Sonos Network Requirements FAQ? Do you have any other Sonos devices already? Is there any Sonos or IKEA device that’s currently (and potentially temporarily) wired to your router with an ethernet cable?

With a tad more information, this community may be able to help lower your frustration. Or, you may want to skip waiting for someone here, and just call Sonos Support directly to discuss it.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network. 

It used to work fine. For a few days on and off.

So yes to the first question as nothing has changed with my setup. Zilch

No other Sonos devices - that answers q2 and q3

You may have not changed anything on your setup, but that doesn’t mean that there haven’t been changes that you didn’t make.

Still no detail, though, so I’d still go with the call to Sonos support. 

It is surprising how much a neighbor’s changes can make to your system. Adding a security camera or baby monitor can make a WiFi channel pretty much worthless for Sonos but things that are more resistant to packet loss won’t show much impact. Even them changing their router’s WiFi channel or it auto-changing can impact your Sonos system.

sonos sucks!!! that's why it doesn't work!! I received three sonos speakers as gifts and i hate them!! i want to take a hammer to them!! i found a bluetooth speaker on the street one morning and it works better than this sonus junk!! what a great company strategy....make sure it doesn't work with the most popular mobile device in the world - that will work for sure.  Hey sonos, ever hear of bluetooth of wifi standards?  It should not be a major network event every time you want to play music .  Instead of fighting apple maybe you should join them!!    too much work.  I’ll just throw them out.  

What are ‘bluetooth of wifi standards”?

If you’re going to throw them out, I’ll be happy to take them off your hands. I’ll even pay for shipping. 

Last 6 months my system is a nightmare. I disappears about every other day, or the 3 speakers are somehow on 3 different systems. I often do a factory reset of a speaker and it says “it has been added but may not appear (it doesn't appear) but to turn it off and back on to finish setup.” Spoiler... it absolutely never appears. I had to get rid of the sound bar because the system is too unreliable to be my family’s main TV speaker. The remaining speakers are in my office, the living room and basement. All secondary areas where it was nice to have SONOS, but we can function without it, since it no longer works.  It used to be the best, but now it is just JUNK. I absolutely hate it.

Also, why can’t I just factory reset all my speakers or the app or both and have them disappear and add them fresh from scratch? The only option is trying to “reconnect” them and it never works. Plus, if the app knows what the speakers are, why can’t it connect to them? After I smash them with a hammer will they still show up?

Likely because of network issues, not because of Sonos issues. Factory resets wouldn’t wipe bad IP addresses from your router, and as such, wouldn’t ‘fix’ anything. 

However, given the fact they’re ‘junk’ and need to be ‘smashed with a hammer’ they’re likely not much I can do to help. Maybe if you were to call Sonos Support directly, they might be willing to take the abuse.