This can be frustrating when it happens. But an important factor may be that lorries carry such huge heavy loads these days, that they just don't have the power to overtake cleanly and quickly.
I can't find any salient data on the 'net but I seem to remember that the weight limits that HGV's are allowed to carry was increased quite substantially during the last 20-30 years.
One of the results of this is that main roads and Motorways are now wearing out faster than was originally planned for. I am not sure how many bridges there are in that cross Motorways, but most of them were built in the 60's or early 70's. As they are now carrying much larger loads, then we may be facing huge problems in the near future, with essential repairs required. I went to Birmingham and back from Swansea recently and there were dozens of bridges involved. Can you imagine the huge congestion that these repairs are going to bring about ?