Why was all of my remaining capital loss of $15,064.00 from 2023 be used when calculating my 2024 return?

The 3,000 limit is the most you can deduct each year on the 1040.  You first offset the loss against any gains you have each year so that can use more of it up. Then after applying the loss to the current gains if there is still a loss, you can take a max loss of 3,000 per year. 

The carryover will first reduce any Long & Short term gains to zero,

• Then it will apply the balance up to $3,000 as a loss.
• If the carryover will not cover or exceed the Net gain the balance of the gain or loss will be posted.

The entire c/o appears on schedule D. It will offset any gains. If there are still net losses up to $3000 will be used with any excess a carryover to 2025