The European Court of Human Rights is hugely important. From the right to an education to the right to vote, it covers and protects all aspects of our lives. The idea of losing it cause of some lies about “boat people” is terrifying and the effect on our lives untold.
There’s a very broad area of what after the fact means.
Unjustly locked up? The echr can set you free.
About to be deported, to a country where you will be executed? You can appeal all the way up to the echr and they can block you from being deported until it’s sorted.
Property about to be unjustly seized without compensation? You can often stonewall and resist seizure while appealing all the way up to the echr.
So they can and do act as an immediate remedy for harms. But they don’t deal in hypotheticals, and it’s fine to have all of these dumb things passed into law providing you don’t try and act on them.
Also many human rights violations don’t make it all the way to the echr. Knowing the way the echr will rule makes other judges reinterpret the law so it’s consistent with our human rights. In the UK, they’re obliged to do this.
Edit: you can tell it’s useful because of all the politicians complaining about our rights.