"gained impact" is correct and usable in written English.
You can use it when you want to say that something has become more powerful or influential than it was before. For example, "The public's support for the movement has gained increasing impact in recent months."
And lastly, we also try to gain impact.
That's the right choice, because the songwriting here is routinely top-notch, the album gaining impact as it plays and the moods shift imperceptibly.
Others, such as the Statue of Liberty in New York City, gained increasing impact on the popular imagination.
As a result, a more eco-friendly constructive material is obtained which has gained significant impact in the construction market.
Market values, exemplified by the use of money as a key measure and medium of political efficacy, have gained increasing impact on how campaigns are run and on how those who are elected govern.
Plant micropropagation on a commercial scale has developed since the 1960s and gained high impact during the last centuries for clonal mass propagation especially of ornamental crops [ 1, 2].
Measuring left ventricular stroke volume and cardiac index (CI) have gained increasing impact regarding perioperative monitoring of critically ill patients either in the operating theatre or on the intensive care unit.
Yet when we glimpse the film Truman is watching, it is as horrifying as ever, and the mini-series gains impact from showing it.
This is most obvious in the large installations of graphic works whose individual parts gain impact and meaning from juxtaposition but are in fact considered distinct artworks.
If you're lucky, the fund can tame its capital gains impact by carrying over tax losses from previous years.
