Still, a single guy with an atgm will take it out easily from 4km away while he won't be detected.
Really?
So a Russian Armoured division is rolling along and gets to a location where there are enemy bunkers with the front covered in anti tank mines and they start taking fire... so they stop and back up a bit while returning fire and the TOS is called up to pummel the mine field and the bunkers... these are ballistic rockets... their range is not enormous but they don't need to have direct line of sight to the target area... they could fire from behind cover... from behind a line of actual tanks with APS systems and ERA designed to take an ATGM hit from the front.... the TOS vehicles would fire and then depart.
This are not engineer vehicles, they are heavy flamethrowers and belong to the "chemical troops" which are part of the NBC protection service.
They are fire support vehicles intended to breach heavy defences or enemies in trenches or minefields.
They are based on tanks to operate in the front lines but wont be operating on their own...
The TOS-1 was developed for infantry support in mountainous and urban areas.
It does not have the rocket range to operate in the mountains effectively, and its use in urban areas would be considered a war crime by most.
Before it was used more in a direct fire support role, ie. a infantry unit entered a city and a TOS unit waited outside the city limits to fire salvos into enemy held building. The range of the old missiles was sufficient for that.
It would not be accurate enough to hit specific buildings, and certainly would not be safe to fire in urban combat where the target building could be surrounded by friendly held buildings...
The arm calls it "wheel of fire" (or something similar), first a unit of Tornado-G fires a salvo, then leaves his position, in the meantime the TOS unit fires a salvo. I guess that´s why the new missiles got larger range.
Which clearly shows it is used to kill people under cover... the first salvo of rockets is the most effective because by the time a second salvo arrives any survivors will have taken cover and would need direct hits to injure or kill. Having a second salvo of thermobaric rockets means even under concrete protection you will still kill...
You can remove mines with everything. Even a shovel. Or your mother-in-law.
TOS operates with armoured units... any enemy worth their salt will have machine gun and sniper and anti armour weapons covering their minefields both to get more kills and to make it more costly and dangerous for the enemy. Sending troops to clear mines will just get them shot.... a quick volley of TOS to clear out the majority of mines and then columns of tanks with the front few fitted with mine rollers and mine ploughs and probably these days a few anti mine robot vehicles means you can cross a barrier the enemy previously thought was a successful block.
They would likely set up anti tank missiles and guns to shoot at the soft flanks of tanks driving down the boundaries of the minefield to find a gap, and of course any actual gaps in the minefields will be dead end traps to line up your vehicles for destruction by hidden ATGMs and your own armour.
By using TOS you can choose where you cross and therefore get surprise against an enemy whose defences likely were set up assuming you couldn't just drive through there like you just did... which puts him on the back foot.