According to the announcement in the official blog of the Ethereum Foundation, support for Ropsten will be discontinued, and the vast majority of the remaining validator nodes will be disabled from December 15 to December 31, 2022:
"Over the past few months, infrastructure providers have gradually stopped supporting the network, and the level of participation of validators has steadily declined. Therefore, Ropsten will no longer be supported by client, testing or infrastructure teams."
Ethereum Core developer Tim Beiko confirmed the closure of the Ropsten test network and called on the developer community to participate in discussing the approach to the future of all Ethereum test networks. For example, to express opinions and suggestions on target networks for stakeholders and developers, end-of-life standards for test networks and much more.
The Ethereum Foundation team recalled that the closure of the next test network, Rinkeby, is next in line. It is no longer a functional equivalent copy of the main Ethereum network, does not support The Merge and will not support future network updates.
However, the Rinkeby test network will continue to operate until mid-2023 to give users and application developers the opportunity to smoothly switch to Goerli or Sepolia networks.
In June, Ethereum developers reported on the successful transition of the Ropsten test network to the Proof-of-Stake consensus algorithm. As part of the transition of the test network, the Ropsten chain based on Proof-of-Work (PoW) and the Beacon Chain "signal chain", which operates on Proof-of-Stake (PoS), have merged.