It's so much worse than I think you even realize, but you definitely nailed some of the key pieces.

It's correct that we don't opt in, that it's strictly not govt, it's corporations (3 of them), and that modern life in the US makes it impossible to avoid playing this game.

Some additional details:

• the 3 companies each keep their own records - usually they match each other closely, but not always
• wrong information in the consumer's credit report is arduous to correct and basically 100% the consumer's responsibility - too fucking bad, whatever outcome this may cause
• the only way to know if our info is being used to fraudulently open accounts is to periodically check these reports (noting the difficulty in correcting them)
• malicious use is such a problem that all 3 "services" ("extortion rackets" is literally more accurate) recommended "locking" one's credit with each of the 3, so no accounts may be created at all
• many stories of kids finding out their parents loaded them up with debt, very difficult to overcome
• the score is a measure of how much lenders can expect to profit off you - financial decisions that are good for the individual are not necessarily good for the score
• evictions, like other records, stay active for 7 years I believe, and having an eviction on one's record makes every part of renting worse and harder

And nothing I've said is even recent insanity, all of that's been true a long time. It's really staggering just how effectively the US has systematized destroying our working class. We've been the global leader in innovating oppression for decades, it's been interesting watching the rest of the world start to catch on just how severe it is here.