So sure "technically" it's not a queue, but in reality its used as a queue for 1000s of companies around the world for huge production workloads which no MQ system can support.
So the competing solutions are: PostgreSQL or Kafka+PostgreSQL
Kafka does provide some extrs there, handling load spikes, more clients that PG can handle natively and resilience to some DB downtime. But is it worth the complexity, in most cases no.
David (UI details) beats Goliath.
Wayland and SDL got support this summer.
And Xwayland has had support for past 10 years: https://www.phoronix.com/news/XWayland-Pointer-Confinement