Coventry has nothing to do with it. One war crime doesn’t justify another in retaliation.
Dresden was not a war crime by even the most ridiculous stretch of the imagination.
The Nazis used Coventry to test something they wanted to try out - the Allies bombed Dresden for a specific strategic purpose: ending the ability of the Nazis to continue the war.
Dresden saved the lives of at least 100,000 Americans and certainly of more Germans than leaving it alone would have.