Lots of reasons: - Code cleanliness: their code almost looks like code golfing. Hard to debug. - Dependencies: everyone has different ways of implementing eve

Lots of reasons: - Code cleanliness: their code almost looks like code golfing. Hard to debug. - Dependencies: everyone has different ways of implementing everything. some are even outdated. some even have stale bots that close legitimate but unattended issues. - Performance: fastify and uWebSockets.js beats express.js on benchmarks. see https://www.fastify.io/benchmarks/ https://www.fastify.io/benchmarks/ and https://github.com/uNetworking/uWebSockets/tree/master/benchmarks https://github.com/uNetworking/uWebSockets/tree/master/bench... - Multi-part parsing: this is built-in with uWebSockets.js. on express your options are multer or busboy. - WebSocket Server support: this is built-in with uWebSockets.js. on express your options are using ws and socket.io. - WebSocket pub/sub: built-in with uWebSockets.js There are better alternatives like the following: - https://www.fastify.io/ https://www.fastify.io/ - https://github.com/uNetworking/uWebSockets.js https://github.com/uNetworking/uWebSockets.js - https://github.com/kartikk221/hyper-express https://github.com/kartikk221/hyper-express