Or rather "collective actions" and "group litigation orders" are a recent thing and haven't become a standard part of the legal system. Not many people on any side who understand how they're supposed to work in practice.

The UK also has a different set of priorities in its litigation culture. You can win a huge payout if you prove unfair dismissal or discrimination, but it's much harder to prove that your work contract is unfair/exploitative or that Service Provider X is operating in a shady way.