GMT is, for these Islands, proper time, with the sun at its height at noon. The amount of daylight has always varied from one end of the Kingdom to the other, but we have managed to get by. BST does no harm, I suppose. But any further deviation would be disastrous, as indeed it was when it was briefly tried. Nowhere should and must have Greenwich Mean Time more than Greenwich.
Our oldest ally, Portugal, uses the same time as us. For some reason, Gibraltar does not. But Saint Helena has GMT all year. There was once a very brief attempt at something called Saint Helena Island Time. It rapidly and rightly became known by its acronym, before it was rapidly and rightly abandoned.
Working people need daylight when they have to go to work in the morning, not in order to prolong their outdoor recreational activities in the late afternoon or the evening. But who asked them? America's so-called Daylight Saving Time has been extended so many times that "normal" time now operates for only four months of the year, and even that is under threat. Golf and garden parties must always take priority.