I bought Flash 5 (not CS5) and later Flash 8 a long time ago, and I still enjoy them,
I use Flash 8 for animations, graphics and even some mini games test. I've tried later versions but it is losing performance since adobe bought it.
So now in 2018 we have plenty of newer tools, like Toonboom Harmony , Unity, Godot
I'll consider a change to a newer software ? I already did on the game development side, I'm using Unity (and still learning) and I consider great for game development.
For 2D animation I didn't take the step out of Flash yet, Because I can render to a video file there's no rushing to a change.
but l CAN'T recommend Flash to newer developers/animators,
The reason for this is because is outdated, and as I said before Adobe messed up and other softwares.
... so why I'm still using it for animation?
- Because I bought it, and I don't want to spend more money for newer software yet
- I use plugins that help me to create assets and animations
- I have experience on it and I work faster on it.
And Flash is great.