Why might my rear wiper blade have stopped working?

It’s not even turning on…i.e. swishing it needed replacing but surely this wouldn’t have broken the internal mechanism? Do you think it’s something that I could sort myself or am I going to have to take it into a garage? I’m seriously broke

If I’m going to have to take it in, will it be better to buy a new wiper blade and fit that myself first to check that that might not be the reason why it’s broken….