I think @jonl might be on the fence with this one 
Without trying to disturb the hornets' nest, I think it's fair to say PHP is not dead and there's plenty of people (myself included) still supporting and developing with PHP, but there are currently some advantages for most use cases by choosing NodeJS e.g. asynchronous processing can be beneficial and many of the most recent additions to Wappler (e.g. sockets) have been NodeJS only and this is likely to be an ongoing theme. It is worth noting that @george has committed to supporting and developing for PHP.