I think there is something important for you to understand.
Komi counts for 1 handicap.
The system didn’t give you “zero”, it took away white’s komi, which is worth 1 stone.
If you don’t accept that this is how it works, you will find it even harder to understand.
Handicap system:
Equal rank: 6.5 komi
1 kyu difference: 0.5 komi
2 kyu difference: 0.5 komi + 1 stone
3 kyu difference: 0.5 komi + 2 stone
etc
You can’t calculate the rank difference by using the APPROXIMATE rank that you see next to your name.
Thats because someone who shows as 17k might be “almost 16k”. Like they are 16.1k
And somone who is 16k might be “only just” 16k. Like they are 16.0k.
These two people are only 0.1k different. They are treated as equal for handicap, even though it is 17k vs 16k.
HTH