I wouldn't despair too much about the calculation of R. Epidemiologists may not be able to give you an exact figure but it is not true that they are merely guessing, in a manner equivalent to that of a coin toss. Nor is it true that lockdown measures have been ineffective. One need only look at New Zealand to refute that, but plenty of other countries show similar patterns.
Perhaps it's also worth adding that you are using a different metric of "success". In the UK, the restrictions were meant not to eradicate the virus, which only a Wuhan-style lockdown would have achieved, but to bring its spread under some form of control and to avoid a situation in which the NHS was overwhelmed. That the Nightingales have gone largely unused is a testament to the "success" of the lockdown in that sense.
None of which means that the sentiments in your posts are wrong, but the starting points at least need challenging.