The cost of providing this service would be huge.
The only rail route between Perth and Albany currently is via Northam. The line from Northam to Albany (GSR line) I think has a maximum speed of 70knh with many much slower sections. Even with major upgrades this route would still be much slower than road transport and therefore would only see very low passenger numbers and would represent poor value for money for taxpayers.
To build a faster more direct route the cost would be astronomical. Even though patronage would be higher it would be nowhere near enough to justify the huge expense.
The only hope would be for a tourist train but even then the capital and ongoing costs I think would still be too high.