That's a pretty silly comment by Costas if he thinks that's unique to baseball.
Just to take 2 random examples...
NBA
In 2014, Terrence Ross, at 22 years old, scored 51 points on 16-29 shooting, 10-17 on 3s, with 9 rebounds. In a close game against the Clippers that mattered to both teams.
Now, in his 11th season, Ross has career averages of 11 ppg on 42% shooting.
NFL
In 2012, Matt Schaub threw for tied for the 2nd most passing yards in a game in NFL history at 547 in a 43-37 win. He was 43 for 55 with 5 TDs.
In his other 15 starts that season, Schaub averaged 154 passing yards per game.
Schaub was 31 at the time & only started 11 more games in his career over the next 7 seasons after that.
I mean I guess technically the bar is lower for baseball because the sample size is much smaller - 4 ABs, but meh.