Thank you for your continued feedback. As many people have pointed out, this is available on mobile today. Support for replying to a specific message is on the backlog for desktop. I’ll let you know when we have progress to share. Thanks.
The engineering team is continuing to work on adding support for multiple accounts on desktop clients. We will first launch support for 1 work/school account and 1 personal account so users can enjoy Teams for work and personal side-by-side. Windows and MacOS. Support for multiple work accounts is still being worked on and will come at a later date.
You can track status via the roadmap here: https://www.microsoft.com/microsoft-365/roadmap?searchterms=68845.
An error occurred while saving the commentSebastian commented
The problem for me is that when a new reply is added, the conversion does not move up in the window, so the reply button gets hidded. Only the 'start conversation field is show' See attached screen capture