Libraries are full of books claiming that the electromagnetic and the weak interactions have been unified. That is wrong! The two interactions mix, but they are not unified. They are different things, remain different, and their coupling strengths remain described by two independent parameters.
This widespread mistake had disastrous consequences. People went around for 40 years saying: we have unified the first 2 interactions, now we will unify them with the 3rd, and then we will include the 4th. Unfortunately, this approach cannot work, because the first 2 interactions have not been unified to start with.
Despite this false direction, unification is what fundamental physics is about. But so far, nothing of the sort has been achieved for any of the four interactions. The idea that the electromagnetic and the weak interaction have been unified is an example of ideology: it contradicts the facts.