> I don't think the UK even has such a resilient system.
Tell that to someone from the UK, and they're likely to laugh in your face. The UK has never faced rolling power outages; Texas faced that just two years ago (although ERCOT appears to have had some issues with the "rolling" part). Furthermore, I don't think the UK has ever had to go voluntary load-shedding measures; Texas had to do that several times this past month, and last summer, etc.
It's hard to say that the extreme cold event was uprecedented when the exact same thing happened in Texas but a decade prior, complete with learnings that would have prevented the breakdown of the grid (i.e., rolling blackouts) had they been implemented. And the extreme heat wave has been impacting, well, more or less the entire world, and most of the power systems haven't even had to suggest that customers use less power. This is stuff that is eminently predictable, and in most of the world, electricity capacity is planned under the basis of extreme demand scenarios, not normal demand scenarios. If Texas's grid is designed merely for normal demand, then that is a surprise that should have Texans up in arms about the incompetence of their electricity regulator.