While it's of course good by local UK standards, I still think sometimes London needs to recalibrate to pay closer to US norms. Cost of living in London is often just as bad as major US coastal cities. At my work, they recently introduced a London office paying eng roles in similar salary range, and lots of opportunities to move there with help provided for relocation fees. For many the interest evaporates when they see typical dev pay package and CoL in London.