First Class exists for ex BR staff holding All Stations and by Ships Passes!
Well, not really but it does come in handy some times. My local services have no First Class so it doesn't apply to me getting to London but for longer, private, journeys I use it.
Back in BR days there were some rather silly restrictions applied to who could use what kind of pass when in which class. I remember being allowed to travel on the 17:00 Liverpool St - Norwich in First with my pass, my wife and two children who were using First cards where you filled in the date couldn't because it was restricted. This resulted in me being in First with my dog and the wife and children being in Standard. That went down well!
I love it, at least you got your priorities right - Dog in 1st Class
I have just returned from a couple of 1st Class journeys on Virgin West Coast from Edinburgh to Sandwell & Dudley and back which I purchased in the recent Sale at £30 a pop. (I normally fly EDI or GLA to BHX).
For my £30 I got lounge access at EDB (Times, Biccies, Crisps, Brew). On board I had a Bacon Roll , Coffee, OJ and then after Preston Lunch. Sandwich,Crisps,Cake , Coffee , Scotch. This is the best sort of journey where you get " 2 offerings" ie B'fast and Lunch. Coming back it was just the full English, Toast, Croissants, OJ, Coffee etc and a Times.
Being a freeloader I am not the intended target for 1st Class and would no way pay a fare in the hundreds - thanks to those of you who do
Another amazing fact is the saps who sit in their "relatively crowded" 1st Class carriage seats to which they are allocated. I always head straight for J or whichever carriage contains the Kitchen as this is unreserved and often empty. You also get better service and "extras" as long as you don't mind the crew yapping.