If your database simply shards keys sequentially, it's going to get hotspots in a lot of use cases, like plain old integer keys and timestamps, not just UUIDv7. In that case it would be fair to say that your database is doing it wrong.
Fortunately, there's no rule that says you should shard your keys using the sequential part up front.
One of the rules for generating randomness from environmental sources is to throw away the high bits and only use the low bits. Distributed databases should do the same if they want a good distribution.
