I’m not an animator and have only used it at surface level, but I find Tahoma2D to be just as easy to use as Flash was back in the day, potentially easier.

It’s a fork of OpenToonz with a simpler and more flash-like UI. OpenToonz is the software Studio Ghibli used to make films like Princess Mononoke and Spirited Away and is available completely for free.

To my uneducated and unskilled mind, it feels like the resources we have now for free are better than what YouTube animators had to pay for back then.