In some cases yes, replacing an old machine with a new one can be an evironmentally responsible choice. But in general that's not the case and one should thoughtfully consider the variables including but not limited to software choice, grid carbon cost (see Electricity Maps below), embodied carbon cost of materials, environmental issues of mining and production not strictly related to climate emissions, and more.

Low Tech Magazine wrote an article about this here:

https://solar.lowtechmagazine.com/2020/12/how-and-why-i-stop...

https://app.electricitymaps.com