The mayor of London has a 17.2 billion pound budget. You would think he could find the few hundred thousand you have highlighted here to ensure some of the most vulnerable of the inhabitants of his city are safe, in particular if the local councils are strapped for cash. In reality all these high rises that were built in the 60s and 70s should be torn down and replaced.
Building regulations are actually quite strict in the US, as anyone who has dealt with a city on permitting issues could tell you. The issue very often in tragic events like this isn’t the regulations, it’s whether the regulations are being followed, in particular for low income housing where every conceivable corner is cut to save cost.