The great problem for Labour is the loss of those safe seats in Scotland where there is a permanent majority of left wing voters who are voting for an alternative party which, whilst left wing, is essentially also identity based.
A similar pattern is affecting them in England where the Tories are morphing into a grievance-based white identity party with flexible ideology. That leaves them with quite a strong coalition as, despite this alienating younger people and some professionals, they've retained enough of their existing base to make it work for them electorally.