

Different framegen techs have different requirements. Some like DLSS and the newer FSR require specific GPU hardware, some require being built into the game specifically. Lossless is great because it works on most hardware and most games.
My understanding here is that it’s working as part of the Vulkan pipeline, but I don’t have enough knowledge in that area to answer more accurately than that. [This article] discusses what the dev of lsfg-vk had to do to get lossless framegen working on Linux, and it can give some insight into how it’s working.
It depends on the game, framegen techs, and your base fps.
It can be a great way to squeeze more performance out of a game in some circumstances, but it’s a big problem when games like MH:Wilds rely on it to meet an acceptable fps at all.