How to remove null values and display non-null values in multiple rows

Your problem is that you have nothing that links the items together. Just because you enter the data in that particular order, does not mean that SQL will return it in that order when you do a select *
You need an addtional column that helps you e.g.

declare @demo table (col1 varchar(30), col2 varchar(30), col3 varchar(30), partitioner int);
insert into @demo (col1,col2,col3,partitioner) values
('ann', null, null,0),
(null, 'dev', null,0),
(null, null, 'ora',0),
(null, null, 'own',1),
('add', null, null,1),
(null, 'dig', null,1);

In this data I have introduced a column partitioner where I have explicitly indicated which rows need to be collated. The problem then becomes trivial

select max(col1) as col1, max(col2) as col2, max(col3) as col3
from @demo
group by partitioner;

If we have a row number available then we could do something like this

;;;with cte as
(
	select col1, col2, col3, rn, cast((rn - 1)  / 3 as int) as partitioner
	from @demo
)
select max(col1) as col1, max(col2) as col2, max(col3) as col3
from cte
group by partitioner;

The row number would have to be defined in the table e.g.

declare @demo table (col1 varchar(30), col2 varchar(30), col3 varchar(30), rn int identity(1,1));

because we can't use the row_number() function without something to sort by. Unless of course you have some other column such as datetimeInserted
Here partitioner is calculated with cast((rn - 1) / 3 as int) which for row numbers 1,2,3,4,5 and 6 generates 0,0,0,1,1 and 1 like the first example.

Edit: N.B. This method relies on the identity column generating sequential numbers, no gaps. This is not guaranteed to be the case. It would be better to have rn as "something that you can order the table by" e.g. that datetime the row was inserted I mentioned above. Then you can guarantee sequential numbers with

((row_number() over (order by rn)) -1 ) / 3 as partitioner