Soul Speed doesn't break boots
The bug
Soul Speed, when used in survival, will allow damage on the boots to reach negative values without breaking the boots.
To reproduce
Run this command
/give @s netherite_boots{Enchantments:[{id:"soul_speed",lvl:3s}],Damage:480}
Then walk around on Soul Soil/Sand blocks for a few seconds and then check the durability of the boots. The damage will be negative. (Make sure to have Advanced Tooltips enabled, F3+H)