I believe PICO-8 (https://www.lexaloffle.com/pico-8.php) is one of the most simple and fun environments for kids to learn programming (specially game programming).
It's very accessible and affordable.
It captures that vibe of an old computer system (where you turn it on and are ready to program immediately) with simplicity and an awesome community to learn from.
id games were some of the best of its time, containing a good mastery of technical and fun gameplay elements.
I´ve made a nice Android app with all the older .plan files documenting John Carmack´s insights on the development of Doom and Quake: https://play.google.com/store/apps/details?id=com.vitoralmei....
Lower the barrier? The barrier IS lower enough even for kids...
Javascript is the basic of this generation.
There aren´t any barriers for new programmers to just sit and learn programming. The tools are already available in the browser. You can learn web programming with your PC, mobile, chromebook, macbook, "any"book.
But yes, I would really like to have more mature and integrated developer tools.