Does anyone still need testnet3?

In a recent discussion among Bitcoin developers, the main challenge identified with using testnet3 is the difficulty for developers to obtain coins, particularly due to high transaction fees. To address this issue, an innovative suggestion has been proposed to create an application that would facilitate swapping coins between testnet3 and testnet4, potentially leveraging an Automated Market Maker (AMM) system. This idea is in the early conceptual stage and would proceed if it garners sufficient interest from the community. The proposal aims to ease the process for developers to access necessary resources for testing and development within the Bitcoin ecosystem.