To be fair you can actually get to most part of the south west by train, it's just slow. As someone whose parents live in that part of the world I'd definitely appreciate faster trains though.

The train to Bath and Bristol (from London) is sufficiently good to use as a daily commuter if necessary (I’ve done it from Bath in the past even before the 2019 schedule reworking), but going anywhere further south west by train is pretty miserable. It’s particularly sad if you look at the pre-Beeching map and consider what could have been there instead.