Hey! Thanks for your detailed review and thanks for mentioning about the licensing of plasma shader, I'll review it later and take necessary actions (or remove/ replace it from the pack). As far as I remember, I've mentioned it if I modified shaders from godotshaders.com. And as you mentioned, yes almost all of these assets can be self-made, but as many mentioned on Reddit, they use this pack as a learning tool.
The pack was initially released at $5 with v1, But I had to increase the price as I push updates (updates are free if you already purchased - so this way I can keep the project ongoing without publishing a whole new project and my early supporters can benefit too) + I introduced Pixel Renderer (it's free & opensource). But EffectBlocks has it's own version with built-in effect spawner. There will be more updates coming on the way - stylized (cartoony) effects and space effects for now, but I have several more in my mind.