For enterprise networks interconnection to the cloud (public or private) can be done with e2e DSCP marking.
This is just part of products available at AWS/Azure w/ or w/o their own interconnection network (direct connect, express route)
and used regularly to ameliorate QoS of RTC applications such as WebEx, Skype for business, WebRTC.
As I said, peering is key and cloud providers are doing that very well. With the current widespread of SaaS and IaaS your app is likely running in the cloud.
Even in case a branch office is connected using SD-WAN, DSCP is tunnelled by it, and transparently for the application.
If working from home, the quality of peering of an SP to cloud providers is key.
I'd say that the Cloud and the decline of transit networks have facilitated DSCP e2e.