There is also just a lot more people who need those things for working from home, which would explain why their are shortages. It isn't just hoarders, there is an actual increase in demand.
Toilet paper shortages are caused by hoarders, since demand hasn't actually increased.
In case of TP, I'd lean strongly towards the problem being caused by the supply chain being bifurcated between consumer and business markets. From what I anecdotally hear, there's plenty of TP available for cheap in the US, just all of it is in absurdly-sized rolls you would struggle to fit in your bathroom.
I can compare that to Poland, where we didn't really have much of a TP shortage. Here, from my observation, most businesses buy the same type/size of TP as regular consumers do, so I suspect our market isn't as strongly bifurcated, and so there was no problem shifting supply from businesses to the stores.
Toilet paper shortages are caused by hoarders, since demand hasn't actually increased.