And presumably they're all selling almost exclusively to the aerospace industry. There's like a dozen COBOL compiler vendors too. It's not indicative of the health of the language ecosystem.
Ada is used all over the place in high integrity computing, that is much more than aerospace.
Well, COBOL just got ISO COBOL 2023 out of the door, and both Visual COBOL and NetCOBOL, still offer a much better development experience than many FOSS toolchains.