The date of the post is from this week so it’s not accurate at all. Java does support main outside of a class now, and it doesn’t need to be static, or take args. You wouldn’t use JavaFX in this day and age either. Installing the jdk is absolutely nothing especially if you’re using IntelliJ as it will install it for you and manage everything. No library is even close to 3gb.
This entire post sounds like it was written by someone that last touched Java in 2010.
Source: am a Kotlin dev. Java sucks. None of these are the reasons why.