React has a mature and well-documented ecosystem, with a wide range of tools, libraries, and resources available. Inferno aims to provide a similar developer experience to React, making it easy for React developers to switch. Svelte, on the other hand, has a unique approach with its declarative syntax and compiler, which can take some time to learn but offers a highly efficient development experience.
React has a steeper learning curve compared to Inferno and Svelte, especially for beginners. React has a larger API surface and more complex concepts like virtual DOM and JSX. Inferno, being a React-like library, has a similar learning curve to React. Svelte has a different paradigm and requires understanding of its compiler and reactive programming concepts, which may take some time to grasp.
Community and Ecosystem
React has a massive and active community, with a vast number of open-source libraries, tools, and resources available. It has a strong backing from Facebook and is widely adopted in the industry. Inferno has a smaller but dedicated community, with a growing ecosystem of libraries and tools. Svelte, although relatively newer, has gained significant popularity and has an active community with a growing ecosystem.