Addresses contain version and checksum information, and address size is variable. There are "only" 2
160 possible addresses.
Brute-forcing an address is extremely expensive. Probably well over one billion dollars. It'll never be profitable to do so.
If every person on Earth makes ten addresses per second for 20 years (2x1018 total addresses), then the probability that two of these addresses collide is about 1.57x10-12.