Freezing is always what you want, that's what they are required by law to provide. There is no law that says they can't also provide something similar and encourage people to pay for that, and that's what locking is.

I recently applied for a credit card and temporarily unfroze (thawed) my credit with all 3 bureaus a few minutes before I submitted the application and was approved.

I’ve never been able to figure out the difference and haven’t cared to dig much deeper. I use the freeze and have been able to unfreeze on the spot when needed (I.e. at the counter at a bank).

From what I could tell the lock is a dark pattern to charge for something that is free and (potentially) less effective than the freeze since, from my understanding, the freeze is regulated where the lock is not.

I ignore that part. I just know that I can instantly freeze/unfreeze. Just did it last week in fact, at all 3.

Locking costs money. Freezing is free.

dark patterns...there's no reason to pay for locking