Hi it isn’t the way the NHS works necessarily it’s a bit more complicated than that. Ask them why when the new paradigm for treatment is to go hard and early. There are lots of resources out there like Barts MS blog which is nhs based. If it is that the team can’t get it past the consultant and they are the gatekeeper then think about changing. You don’t say where you are but there are some really laggard neurology departments out there. You’ve had MS for 12 years smouldering away so starting on some outdated treatment that was the only thing available 12 years ago may not be the best choice.
Wishing you all the best