Yes, from the UK there are a lot of LCC alternatives. As long as you travel between places where there is a lot of demand then chances are you have a FR or W6 or ... option. The great strength of traditional carriers is that they can offer connections and pad their loads with pax between smaller local markets or a local and intercontinental destination.
If slots at CDG or ORY were made available to FR, that will not change, though I'm sure a lot of French would appreciate the option.


LO at KSC - yes, from the beginning. Along with the early afternoon rotation. This pattern is kept by OS and was also kept with OK in the period when they had 2 daily flights. KSC is the type of outstation where you need that late arrival and early departure, it's big enough and close enough to some alternatives that the pax demand the option of flying out first thing in the morning and reaching a major market before lunchtime, conversely leaving after EOB and still getting back before midnight. The late evening arrival is also practical for incoming, arriving evening before, the departure not so much. Afternoon rotation helps there, and also with intercontinental connections. Plus allows you to rotate crew with full rest (albeit you have to put two sets of crew in a hotel). OS do that, crew from the night before have a full rest and operate the afternoon flight. Not sure if LO did the same but I think so.


LO at TAT - I think that option is killed by S7 road. It no longer makes sense for leisure market to prefer air travel when you can do the same in a car in 5 hours. When LO was active at TAT it was over 7. Local market on Slovak side is adequately served by KSC.
I am more interested in whether BT is ever coming back (at the beginning of their service, they did it as a tag-on to RIX-WAW. Maybe that could work again? Presuming BT will get back on that route as well of course.