One address 2+ private keys. Bitcoin future

[Bitcoin]

One address 2+ private keys. Bitcoin future

Since bitcoin uses cryptography algorithms to create private and public keys there is a possibility it could repeat.

Person 1:
L54w...KraG -> bc1...kq4

Person 2:
L3mV...JU8G -> bc1...kq4

So could person 2 single handedly sent bitcoin from bc1...kq4 to a different address. My question is would both of the private keys work to change the funds. If so how will his affect bitcoin as a whole.

Source: One address 2+ private keys. Bitcoin future