As Switzerland's strategic reserve, the army has a broad array of tasks, ranging from support in low threat levels (current example: preparing for the storage and distribution of Covid vaccines), supporting the police (example: World Economic Forum) to high threat levels (where tanks and artillery are needed, so this is also being trained for).
In the end, the Swiss Army is the Swiss Army knife for Switzerland's national security. Articles like this one that talk about defunct bunkers that were built for a very specific cold war scenario (but again: are now decommissioned) naturally don't really help.
Furthermore, the 'bottomless barrel' also completely misses the mark, as Switzerland's military expenditure is very low (around 0.7% of the GDP, NATO benchmark is around 2% for comparison).