Because I’m in my very early 20s I missed out on the huge Java craze. Everything was Python when I started getting a more formal education and before then all my work was in C++. Knowing more languages would obviously look better on a CV but I mean if I would benefit in a practical sense? I have two friends who are long time Java devs. And recently another friend who generally works with legacy C++ based systems from the early 2000s late 90s period had to work on a bunch of stuff in Java. Java is clearly still in large scale use among older systems. So would it be likely that eventually I would need to work on Java systems myself when my job is mostly JavaScript currently?
I used PHP voluntarily. 22 years ago there wasn’t much choice. Java hosting options were expensive, Perl options were more expensive than PHP, C# didn’t exist (this was the same year it came out!), Python 2 wasn’t commonly installed by default on Linux distributions etc. No cloud, no Node.JS. If you had access to Windows server you could use VBScript - if you targeted Internet Explorer (versions 4 and 5 were dominant, 6 was new, it was the most popular internet browser at the time) you could use VBScript for both server-side and client-side scripting. Java applets were a thing. But if you didn’t need that, PHP was the most accessible option. And since many hosting providers gave you similar versions of PHP and its libraries, you knew what could work and what not and that you could move your website from one hosting provider to another.