The simplest solution is probably the ikea symfonisk sound remote and an ikea smart hub, which link up with sonos out the box, due to the sonos + ikea symfonisk speaker partnership.
If you already have an ikea smart hub for lights/blinds it’s probably the cheapest at £19 for the remote.
The new sound remote isn’t as nice as the original rotary one, but you can use normal rechargable batteries rather than the button cells of the gen 1 remote
https://www.ikea.com/gb/en/p/symfonisk-sound-remote-gen-2-90524607/
It gets a bit pricey as a single remote control if you need to buy the current ikea hub £60 as well though.
https://www.ikea.com/gb/en/p/dirigera-hub-for-smart-products-white-smart-50503409/
I already had the hub for lights and blinds. So just needed remotes. For volume, play/pause/resume they’re much nicer than having to fiddle around with phone/tablet apps. Being wireless you can put them wherever is convenient in the room. In a morning I wander downstairs to the kitchen and press the button for the last items in the speaker queue (custom queue, internet radio, local album, whatever) to start playing while making coffee.
I had them in all my rooms with Sonos speakers and have attached them to my current system after moving away from Sonos.
The Gen2 square remotes can also have 2 favourite sources assigned to the left/right clicks I think.
I think Lutron does volume controls using the Pico system, but haven’t kept up with them, it may no longer be a ‘thing’.