Well, with silver this intrinsic value/price tag ratio is especially bad. If a 1oz coin costs around $30, a half oz should be $15 and a quarter oz $7.50 - but they cost basically all the same to mint, and the dealers dont want to do the work for $0.50 a piece or so. Thats why you dont see the small coins very often, although they do exist. The Mexicans make them, the British also, and I assume some others do, too.
The situation is very much different with gold coins, though, because there the ratio of material value and minting cost is totally different. Yes, also gold coins are more expensive per gram, the smaller they are. But in a much different ratio. And there is more demand for smaller coins, because not everybody can afford to spend $1800 for a whole 1oz coin. I have seen 5g and 10g coins, and even tiny little 1g pieces.
But in Germany all this is also connected to certain tax regulations that we have here. Like, gold is tax free, silver is not. And silver coins (legal tender) are taxed lower than silver rounds or bars. All that plays into the decision making when we buy bullion here.

And a happy new year to you, too!