Even if you think there should be a social safety net for these types of circumstances, it makes little sense for employers to provide it. For one, it has the usual problems of tying important services to employment, similar to how healthcare is in the US. It also puts an undue burden on small businesses. You run a 10 person startup and one of your employees got a long term disability? Congratulations, you have to now find a replacement AND continue paying them. Large companies have law of large numbers on their side, but as an unlucky small business that's 10% of your payroll.
>Edited to add: this is not the mention your employer might just pull some crap like nepotizing a promotion over you, where a union would come in handy handy!
1. has there been a good track record of unions being able to successfully prevent cases like these?
2. Given the level of corruption associated with unions, at least in the US, you're just replacing one problem with another.