The length of it is exaggerated on the map due to map projection (obligatory comment). In reality it's about as long as the one connecting Oregon to Taiwan (which is long, but not record-setting.)

Probably a pretty important project to do that one for Russia anyway, it connects all parts of the country.

That made me think that laying underwater cable must be very economical. There's lots of loops that look completely unnecessary, like the Gulf of Mexico. But maybe it was cheaper than installing cables on land? And the terrain of Northern Russia is probably a lot harder to deal with than Texas.

Cheaper but typically a longer route which translates to higher latency.

As a standard internet user the difference between 20ms and 24ms might not matter to you but when selling enterprise services, especially around financial institutions (but not exclusively) that 4ms matters. Often it matters enough that the business case for terrestrial cable starts to make sense.

> But maybe it was cheaper than installing cables on land?

Way, way cheaper. Trenching or tunneling on the one hand, mostly just steaming forward whilst paying out cable on the other. The cable itself is more expensive for submarine use though, so there would be a point where cost crosses over.