MAN-SOU as a daily service operated at x times per day was predicated on high price business travel to make that pay, that's showing no sign of returning to the same level.
I never contended that business travel would return to the same level. On the contrary, I made it very clear that business demand is reduced (but not extinct). I also made the point that not all business travel is about folks in suits attending meetings. Sometimes one just needs to be on location.
Hence you might manage to make a once daily rotation on a prop work BUT that's going to have to be at a relatively high price point AND you need 2-3 other rotations for your aircraft out of MAN or SOU.
It is your OPINION (not an established fact) that MAN-SOU would support only one 74-seater per day. But it supported SIX daily previously. I contend that your antipathy toward the route is overdone. My suggestion was for TWO daily flights initially (one third of previous levels), with a third to be added later if uptake justifies it. That would still be only half the previous capacity. Keep in mind that cross-country railfares are themselves crazy expensive, and short 'Voyager' trains feature on many services (if they're not cancelled or on strike). Good luck getting an actual seat on the train too. There are NO new paths (for additional rail services) coming to the main North-South routes, because our wise politicians have KO'd HS2 which means that capacity will not be released on existing lines. So rail prices aren't falling, the road journey is an ordeal, and plenty of folks still need to travel between Manchester area and Southampton area even if elevated prices apply (as they do on the trains).
if SOUMAN was such a gold mine why didn’t they operate it?
I don't recall referring to SOU-MAN as a "gold mine". It is, however, a much-needed route with a long proven track record of viability. I have no inside information to confirm why FlyBe 2.0 chose the launch routes they did; perhaps they got attractive terms from the bases they chose? But the immediate problem for UK regional airlines generally is access to crews, spares and aircraft for expansion / replacement of older types. I suspect - but cannot confirm - that this is why Loganair has not yet followed up on slot applications for the SOU-MAN route. Those on the SOU thread speculate that there was some bad blood between Southampton and Loganair, but I am in no position to comment on this one way or the other. I just note that the narrative is out there.