alt Hacker NewsAustralia hasn't had a POTS for a while now, since the National Broadband Network was "complete". They literally ripped the copper out of the ground and sold it for scrap, they even made specialised machines to make the task easier: https://www.rg.com.au/2022/09/29/telstra-mirait-take-deliver...
Hasn't really been much of an issue day-to-day. My mother for example still uses her landline phone on the same phone number she's had for decades via VOIP that the ISP operates. The vast majority of people use mobile phones as their primary voice service and it all seems to work just fine. But there has been a few notable outages (e.g: Telstra and their NTP mess, Optus and their emergency-call routing issues), and of course there's fringe issues with coverage gaps, but overall I'd say the mobile voice network is as reliable as the old POTS was (which was far from perfect).
Still copper up my way mate - Even though the pair gain technology improved things for a time, golden days would be 1990s here, the service rendered got worse and worse. Present times it's not surprising to see a simple phone only landline down for months. For example my Dad's line - Telstra can fix the landline and it'll be dead again within a couple of weeks ... if only reporting took a couple of minutes but Telstra has ensured it takes up a couple of hours for each instance by phone, even using the chat bot path, the last time a year ago it still took a couple of hours based on the repeated sessions to finally get a technician to arrive, confirm and head back down the track to bodge the line and get the service up ... it lasted almost a month ... a sibling got him a mobile phone (given location somewhat limited) in the end.