Experian should be illegal under GDPR. It operates without the user/victim's consent and the victim has zero rights over the data collected, much of which can have a drastic effect on the victim's life. I can't believe Experian exists.
It's probably worth pointing out the alternative to centralized, reasonably deterministic credit reporting is basically hard dings (e.g. known missed payments) & bank statements and income. This locks credit availability even more directly to your wealth and income position. Credit reports, at least, are a broader model of behavior whose inputs are well understood and relatively easy to track with free apps like Credit Karma & other competitors.
This may be trickier to demonstrate than you might think. It could be that every credit card you use has Experian as a data processor, and that the only way to disengage is to stop using the credit card.
It seems like you could make good arguments for libel and tortious interference.