The packages in Debian Stable are old. They're old when the release is new. They're even older when it's a year and a half into the release and a new Debian Stable is still 6 months away.
Even the kernel is old. The applications are definitely old. The developer tools like programming languages and IDEs (if there are any) are old.
Does any of this matter?
There are workarounds if you must have the latest versions of a few things. And if you want the latest of everything, there are other releases and distributions that offer it.
But what if you really want those improvements? After using Linux and BSD for years, I've come to learn that latest doesn't always mean greatest, and being on the edge often brings new bugs along with it.
That's not to say that you can't run newer software in Debian. There's always the Testing and Unstable distributions, though even those I find to be behind Fedora and Arch in almost all cases.
There are some newer packages in Debian Backports. And now software packaged in the Flatpak format can run on Debian Stable. Since Buster is very IDE-poor in its repos, I have successfully used the Flathub site (where Flatpaks tend to live) to successfully install and run Apache NetBeans and IntelliJ IDEA Community. I haven't yet tried Eclipse, but Flathub has it.
Why none of these big-time Java IDEs are in Debian is another story. Eclipse and NetBeans weren't "ready" when Buster was frozen, and I think there are licensing reasons why IntelliJ is not in Debian. Flathub means you can get all three with little hassle.