As for having "little intention of selling" I don't buy that. Because then what would you buy physical silver for in the first place...just to weigh down your basement floor (or wherever they store silver) for eternity no matter what? No, the idea behind stacking for those stackers who hold longer than others is as a store of wealth. You don't store wealth indefinitely and permanently no matter what circumstances arise. So, there is always the intention to sell (or exchange for goods and services)....even or especially if the current currency collapses. In such a time, these stackers (according to what I've been reading) believe that silver will hold some significant value greater than worthless.
There is a diverse group here and I can't speak to their motivations, but you have raised some good points and I can attempt to address some of them.
When I started out stacking you could buy silver for under spot value, it wasn't seen as an investment because it seemed to stay around the same price and gradually seemed to increase. This was before I was aware of daily price charts and bullion dealers. I mostly bought round 50 cents and predec off ebay and the prices were pretty stable.
At that time most of the articles I read described silver as a 'hedge against inflation' i.e. you could buy it now, and sell it in 20 years time and get back the same amount of purchasing power as it took to buy it all those years ago. Silver would go up at the same rate as inflation, getting more expensive each year, in line with inflation so when you go to sell you haven't lost out.
I treat it as an off-the-books, free-from-government-or-bank-interferrence, savings account. As such I have no intention of touching the savings account until I have something to spend it on. It isn't an everyday account, physical silver is too cumbersome to sell everytime I want to fill the car up with petrol or buy groceries with.
I could just put the money into a savings account instead of buying silver, but then the interest I earn would be taxed and at the end of it I might just about break even when you take inflation into consideration. But all that time I run the risk of banks shutting down, bail-ins and the banks using my money to perpetuate their fractional reserves or whatever other schemes they have thought up to make money out of nothing.
Now that I have a few more loans out I might just cash in the silver and use the money to pay off the loans quicker, which is what I would have done with a normal savings account anyway. The difference being that my savings account only has a couple of thousand dollars in it and my silver holding has increased because I have never gotten around to selling any.
So I pretty much just buy silver when I have a bit of spare cash at the end of the pay period and put it in a big pile until I need it.
But I also have my numis and some coins to speculate on, those I am happy to sell whenever the price is right. If I had kids then I would probably pass on the silver, as many members pass on their coin collections to the kids for future resale, a way of passing wealth down the generations. In the UK I think they still tax you when you die and I am not sure why Australia hasn't jumped on the band wagon, it will probably come. But by having something like silver that is not registered anywhere this would not be difficult to achieve, until the kids decide to sell it all and put the money in the bank, then I guess they will have to explain where it all came from.