Normalization is possible but not practical in a lot of cases: nearly every “legacy” database I’ve seen has at least one table that just accumulates columns because that was the quickest way to ship something.
Also, normalization solves a problem that’s present in OLTP applications: OLAP/Big Data applications generally have problems that are solved by denormalization.
Also, normalization solves a problem that’s present in OLTP applications: OLAP/Big Data applications generally have problems that are solved by denormalization.