Australia is becoming more white collared, I suppose; we obviously don't manufacture like we used to, less labouring etc. Not many white-collared unions out there. And if there is, membership is fragmented, and a union will have limited effectiveness. OTOH if you have a vast sea of people with basically the same job eg. holden workers, nurses, public school teachers; all going through the one employer; a union can be useful in collective bargaining. Imagine a High school principal negotiating 50 different individual teacher awards? Would be time prohibitive. Also, in some industries and large organisations eg. healthcare, education, a union can be useful if you strike difficulty with policy, protocol, difficulties with management etc.
That being said......unions do need to be very wary in looking for pay rises, for if you are in the private sector it will automatically mean your business you work for is less profitable. If your business is on shaky ground, it is utterly stupid to ask for anything more. This is where the auto workers came unstuck. If they pulled their head in and were a bit flexible, there may have been a difficult outcome. I also think it is unethical for a union to go out in solidarity with another over an issue that does not affect them, however I don't think that happens anymore. For the public sector, unionists there need to realise that there isn't a bottomless pit of taxpayer funds, and money spent paying say police more means less can go to healthcare, for example. As such, any increases should only be kept to CPI, unless there is productivity improvement.
That being said I do not recall any strikes occurring anywhere in the last 5-10 years that were publicised in the news. Unions are no more militant now than they have ever been. If you want industrial trouble, look to the 70s and 80s.