[teddyh]

That person’s entire criticism of Dia is “it’s old”. That’s it; not even “the program, when I run it, looks old”! They merely criticize the web page for having old screenshots and support for old operating systems on it.

[lloydatkinson]

It’s last update was ten years or more ago, doesn’t support HiDPI screens, shall I go on?

[teddyh]

Feel free; the link you provided certainly did not have anything concrete.