Correct. But HGV, coach, SUV, small car, motorbike, moped all are subject to the same 20mph limit though, regardless of the kinetic energy, manoeuvrability argument. The only road users capable of doing more than 20mph that aren't subject to this are bicycles. I'm not convinced that cyclists should be a special case
There are, undoubtedly, more pressing matters regarding road safety than this. However, the tortuous arguments as regards why cyclists should never be subject to speed limits, under any circumstances, are interesting