There is a good discussion of the tradeoffs here [0]. It is often fine expose UUIDv7 publicly, e.g. if the event time is not a secret and you use good entropy for the non-timestamp bits.
However, sometimes you might decide that you care, and use a random identifier instead. In those cases you probably won't benefit from a second UUIDv7 identifier, since you're already paying the cost for a primary key index, but perhaps if you are also doing certain kinds of range queries and have a certain kind of storage engine you still get something out UUIDv7.
In other words, it depends. And it might not matter at all if you don't have much data, and/or it's not being generated in a distributed way, and/or you're not doing range queries or partitions in a way that can take advantage of it.
In other words, it depends. And it might not matter at all if you don't have much data, and/or it's not being generated in a distributed way, and/or you're not doing range queries or partitions in a way that can take advantage of it.
[0] https://news.ycombinator.com/item?id=45622045