Not the reality in sectors that already do this, like the civil service, but it will cap the upper limit that people can negotiate to.

Even if the minimum does apply everywhere, it fixes the inequalities gap that is causing so much economic drag in the UK: white men earn significantly more than any other demographic today for the exact same roles at the exact same companies. If everyone gets the bottom of the band, at least everyone gets the same, and that’s been an important goal for multiple UK governments of different political stripes over many decades for reasons to complex to go into here (and no, it’s not “political correctness”, it’s far more complex than that).

I also don’t think it likely means average salaries come down, I just think it means the distributions narrow.