With a wildfire there's no point in fighting 99% of it - you fight the edges that are near people/property, try to contain it, and wait for rain and for it to run out of fuel. So of a 1000 sq km fire it may only be a few dozen linear kilometers that are being actively fought.

This is the correct answer.

From a forestry management perspective, you don't want the forest to live forever, and trying to prevent old, dead trees from burning is a nightmare. Let the fire burn, protect the property, and the forest will reseed itself during the fire.

By the time Russia came along, much of the populated area's were out of harms way. Adding more aircraft that are all using 1 or 2 airports is just more congestion.

An advantage of all Soviet-era planes is they can use any crappy airfield without breaking a sweat.

Russian firefighting aircraft are sea planes they are designed to land in a lake or in littoral waters to take on water they've been very successful at fighting fires in Greece and Israel with using the med as their water supply.

They don't land just anywhere, plus you need a tower to coordinate them, and Ft. Mac is hardly a bustling metropolis.