Downside of using negative values?

I recently read an article on Bitbucket about “Don’t start identity columns or sequences with large negative values” and it got me wondering if the author’s conclusion is correct.

So I set up a lab to test his hypothesis. Each table has about 4 million rows.

And to mimic the property of IDENTITY, I then rebuilt the indexes on the tables.

And then I executed these statements to see if there was a difference in compression, as the author stated.

And as I suspected, there was no difference.

The reason is how page- and row-compression is implemented.
See whitepapers here

https://docs.microsoft.com/en-us/sql/relational-databases/data-compression/page-compression-implementation?view=sql-server-ver15

https://docs.microsoft.com/en-us/sql/relational-databases/data-compression/row-compression-implementation?view=sql-server-ver15

And to be fair, I did the test again with ROW compression instead of PAGE compression and here is the result

Again, there is no difference. The miniscule 8KB is within the error margin.