We need to have realistic expectations to what unions can achieve. In such a crisis situation as we are facing now, the Unions are fighting with very little in their arsenal. Many feel let down by union for not performing miracles, and unfortunately you have divide created by companies, who try to divide and conquer the unions to bust them.
The real effect of the unions can be felt in the good times, and it depends on what people are willing to sacrifice in the good times, for the good of everyone.
Also labor laws example in the UK are very poor compared to most European countries and even compared to the USA, where the unions are very strong.
The unions need their members support and engagement in the good times, to be able to negotiate good agreements that will cover them for bad times like now. It's hard to start making changes when the house is already on fire, rather we need to ensure that there is a solid framework in place before the fire starts.