I think the chances of Sonos making dedicated controller hardware are zero. The CR100 was built like a brick privy and was essential back in the day. The CR200 was a bit of a wheel reinvention (in terms of a touchscreen handheld) which didn’t go so well. 

I’d suggest you look into something like the IKEA Symfonisk sound remotes. They do need a hub, but once that’s installed you can have multiple inexpensive remotes lying around (plus all the other goodies that the IKEA smart home range offers). Note that the IKEA Dirigera hub does require Sonos S2 though, so you’d need to swap out your Play:5/gen1 if you still have it. 

Alternatively, if you want a shared controller device that can run the full controller app, consider a cheap tablet such as an Amazon Fire.

Another option although expensive and really does need the household using Hue lighting is the Rithum light switch.

https://rithumhome.com

Besides the fact that smartphones and tablets replaced the need for the CRs, there is also the fact that much of Sonos business is in home theatre, where the TVs remote can handle volume controls.  Then as PO pointed out, there is airplay 2 and other casting features where you can control Sonos via a music service app.  So the overall need and market size for a remote device has gone down.

However, I think Sonos could make a relatively cheap remote for all the device in the current lineup that work on BLE. It wouldn’t be able to do anything you can’t do with the current hard buttons, but would be a nice option.

Well that wouldn’t help the OP’s kit which all pre-dates BLE. 

A practical consideration of a remote that worked over BLE would be how to pair it. The latest Eras have a BT button which perhaps could be adapted. Arc, Beam et al don’t. This could mean a configuration UI of some kind to target the remote. Via a BT connection to a mobile app perhaps? It soon starts to become less simple...

Yes, I would like to see a simple Sonos ‘remote’ too - something like the attached, perhaps? (just a mock up based on an already available remote that can be used with all Sonos HT products, via infrared) - if this could be used with all Sonos speakers, without a hub. I would buy several to leave about the Home.

The only reason I don’t have the ones currently available online, is I don’t need them with a HT, as I simply use the TV remote instead, but if these remotes could (somehow) be used with any/every Sonos device then I would certainly buy them - that’s if they retailed say in the region of the £/$/€50 mark.

£50 for something which only does vol +/- and mute?! Good grief. The current IKEA remote has transport control, vol control, and a couple of custom preset buttons for around £16. 

I thought it a reasonable price without involving a hub, but if it can be sold for less, then of course I’m happy with that too.

When I bought my Tradfri kit the hub was £22, or effectively £2 per remote (ignoring all the sockets and lights it also now controls). Granted IKEA have pumped the price on the replacement Dirigera hub quite a lot, at £60, but it’s supposed to do a good bit more. The cost when spread across a population of remotes is still quite small really.

I’m still smarting from what I paid for the now-defunct iPort remotes… 

I mostly use the iPad and/or Alexa/SVC, but a few ‘handy’ remotes dotted about the Home would certainly be helpful - I have ‘old’ hubs for lights (Hue). Blinds (Louvolite), TV control (Logitech Harmony) and Heating (Hive). but haven’t (yet) bothered with Sonos remotes - as I would prefer something without another Hub - it’s something I’ve considered, but have just put off, to see if anything better perhaps comes along.

I think there’s quite a good case for a little remote, but not seen anything yet that appeals, but clearly the IKEA remotes/hub have been in my sights. 

If there isn’t a hub, then what would a remote connect to? WiFi is quite ‘expensive’ in terms of power/energy requirements. The tiny rechargeable cell in my iPort remotes lasted maybe a month or two. A few minutes after the last button press they went into a sleep mode to conserve energy, and WiFi reconnection could often take several frustrating seconds’ wait.

Hubs have the virtue of gatewaying to much more economical wireless technologies such as Zigbee, Z-Wave, or even Thread. They can mesh, and also help preserve IPv4 address space. And in my experience the IKEA Zigbee remotes are extraordinarily responsive. 

Yes, I guess using a Hub maybe unavoidable - nice though if Sonos were to perhaps do their own ‘basic’ remote with just some core functionality.

I often read people say you can just use your phone as a controller and cry. I set up a Sonos amp to play through a speaker in my bathroom a few years ago. The cr100 was deliberately constructed to be waterproof with physical buttons and worked flawlessly without any lack of response. Until Sonos killed it. I think they envisaged it as a pool side accessory. You can’t immediately change the volume using a phone with soap filled hands in the bath. And it didn’t need an extra hub. I don’t want unreliable voice control. I got the iPort and it died; didn’t like the steam I guess. My cr200 also broke but I think everybody’s did. Please bring back the cr100.