For a long write up with more data and some reasons for it:

https://bsky.app/profile/did:plc:ql4ykel4bgsqzslwsa3lflh2/post/3lcdewkbmf22w

Keep in mind Russia is a massive country and trains are amazing at transporting freight over long distances. So they have a lot of regions and industries depending on the railroad. Much more so then in most other countries. Some places can hardly be reached by road, but can be reached on train.