@IsaacFL
You can have a lot more than 8. I don't know if there is a limit. Probably each OS might have it's own limits.
Both Linux & Windows have 8 addresses, after being up for a week, with a new one each day
One concept of multiple addresses on an interface is for each service on the host to have its own GUA. That way you don't have to worry about port conflicts.
There are also privacy addresses with SLAAC, which change daily
That was one of the reasons they decided on 64 bits for the host part of the address so that they could be randomly generated by the service with a reasonable chance that it wouldn't be a duplicate
Also, to work with the EUI-64 MAC addresses. EUI-48 addresses are converted to EUI-64 by inserting fffe in the middle.
On my own network, I have both GUA and ULA addresses, 8 of each.