The block plugins need to go away. Or at least increase quality control. My experience with them so far has been that just installing the plugins, without even using any of the blocks, have dire consequences for the site's performance. Google's Page Speed Insight immediately drops. It's particularly bad with some of the bigger names such as Atomic Blocks or CoBlocks.

While I have no clue about the underlying tech, I have always wondered why new blocks for the block editor have to be delivered by means of a plugin. There should be a way to "natively" add new blocks without the overhead of badly written plugins.