Well, that's the current rules. Now this might still change (for ZRH, FRA, or elsewhere), if the US gets added to the quarantine list again. Canada was recently added to the Swiss list, with immediate effect.

Regarding the hotels:

I tried a dummy booking in the Frankfurt transit hotel for 2 adults and 1 child: Not possible.

If I just choose 2 adults (and assume the Germans would ignore the child - and considering Germans are very strict, they might very well not), it's 174€ for 6 hours, 214€ for 8 hours, or 234€ for 10 hours.

For their cheapest, indoor-facing room (No windows, no daylight)

Meanwhile, in Switzerland, a double room costs just 79 CHF (approx 71€) for 6 hours, or 99 CHF (approx 89€) for an unlimited day stay.

With a 3-bed room costing 99 CHF (89€) for up to 6 hours, and 119 CHF (109€) for an unlimited day stay.

So the Swiss transit hotel is quite a bit less than half the costs of the German one.

Now with 2 adult's long haul tickets in mind, that's probably not that much of an addition to the total flight costs, but it's quite clear the Swiss hotel is offering much more economy prices, while the German one really is designed to charge you rather massively (considering their day rate is like half the costs of what an intercontinental economy class ticket used to cost..)