Yes this would be an issue for me too. And lightroom is really a pretty amazing editing application - Affinity would have to blow it out of the water to make a big impact.
Off topic but; I dont mind paying a sub, so that’s not really a factor for me. What I want is lightroom for the iPad to be able to edit from a hard drive the same as classic can, and for round tripping in to my choice of external editor (wouldn’t mind PS if it was up to the same standard as AF was on the iPad, but it’s not yet), to be possible in the same manner as the mac can. If an Affinity DAM catered for me in this respect then I’ll go through the pains of whatever I need to do with my 10 plus years lightroom library to make the change, as I did with the demise of aperture.