You might not be recognizing them as state adverts, because Switzerland has the largest amount of government advertising of any place I've ever been. By far. If you can't see that you're either unfamiliar with other places or not recognizing the ads as coming from the state. Recall that the definition of the state also includes government-owned companies like SBB, ZVV, EWZ, ZKB. Adverts by any of these companies is an advert by the state. That's a generously narrow definition: it's not including advertising for parties or referendum positions, which saturate billboards any time there's an upcoming vote, nor advertising by state subsidized industries like farming.
Here are some examples.
Walk down to Bellevue. Start to walk along the lake to the China Garden. You will walk past some of the most prime advertising real estate in the city. There are several billboard signs in a row right at the top corner of the lake. Highest footfall of anywhere in the city outside of Bahnhofstrasse itself. When I did this yesterday every single ad was by government, for government. For example, one of them is currently advertising the government-run Native American Museum:
Walk down the lake and you'll encounter more such billboards, all showing government ads. In fact I don't think I've ever seen a non-state advert on any of these places.
Go to a Filmfluss event. It starts with 10 minutes of ads. On Saturday when I went to a showing with my wife, I counted and around half of the ads were by the state. Amongst others: multiple recruiting ads for the Stadtpolizei, ads for ZKB, multiple ads for EWZ, ads for state-funded cultural events etc.
Get on the train or tram. Look at the billboards inside the carriage. Many of them will be ads for the SBB's own services or offers, or recruiting ads for drivers (especially popular at the moment), or the Gemeinsam Vorwarts campaign. These are all state advertising.
If you see all this and really think it's very little then I don't know what to say. Go spend some time in other places of comparable size and pay close attention to how many ads are by the state or state owned companies. It will be lower.
Of all the text the op wrote that is definitely a personal and unfair interpretation and not what he written.
His point is clear: If the goal is reducing visual pollution then a state advertisement is just as polluting as a commercial one.