The year was 2021: Windows was starting again to support non-x86 hardware architectures, and Microsoft was shipping the best to Linux desktop experience. Mac OS shipped with the the fastest mobile processor in the world. Android basically owned the phone market.... Linux desktop was just getting somewhat working basic screenshot support.
To be fair it was only Flameshot that was kind of missing Wayland support. There were / are other alternatives specifically made for Wayland: saying that the whole ecosystem was lagging behind becaude of this specific app is a bit of a stretch.
Yet, it doesn't have a proper highlighter pen. It draws a straight line and adds up. If you go over the same spot twice or more text might become unreadable and it will just look wrong. I have been unable to find a Linux screenshot tool that does it right. I use Flameshot on Linux too, but it's the least bad one in my book.