Lubuntu is the Ubuntu flavor with the LXQt desktop environment. LXQt uses Qt. For those who don't know, Qt is a powerful, cross-platform development framework used for building native-looking GUI applications that run on Linux, Windows, macOS, and Android. Qt has its own IDE (Qt Creator) and extensive tools and libraries for developing, and the apps are capable of using a single codebase across different platforms and even.
One of the many things I love about the Linux operating system is the vast array of choices available. If you don't like a distribution, find another one. If the desktop environment you're using doesn't suit your style or needs, consider installing a different one. If you need something faster, try a lightweight distribution. Given the vast number of distros available, there's almost no end to the combinations you can find.
RedoxOS is a special kind of Linux distribution that uses a microkernel and is written in Rust. For those who don't know, Rust is a programming language well-known for being fast. I've been using System76's COSMIC desktop environment, which is also written in Rust and is lightning fast. Imagine an entire OS written in that same language. That's what RedoxOS is, and it's zippy. This is, hands down, the fastest operating system that I've ever used.