>
The idea that critical communication infrastructure must be (directly or indirectly) supported by advertising interests is certainly not obviousI think the problem is more that the trend over the last 5-7 decades has been to privatise things. The EU (for instance) has rules forcing (e.g.,) privatisation of train companies and postal services. This has caused previously government-owned services to be privatised.
In this day and age, I'd be surprised to hear of any successful case where a non-public good was made public in a Western country. (I'll restrict my surprise to there because of insufficient familiarity with other countries to make such sweeping statements.) Whether it'd be web browsers, water treatment facilities, energy-related, healthcare-related, infrastructure-related, etc.: if it's currently privatised, it will emphatically not revert to public; if it's currently public, it might be forced to be privatised.
You might think about "privatised-but-with-strings-attached" variants, like in California with "carrier-of-last-resort", or in EU with public transport concessions requiring also services that operate at a loss to service small population centers / unpopular hours. Typically, these impose restrictions on the market parties on what they must deliver in order to be granted the concession. That seems like a way to guarantee the kind of service a government would deliver, but by market parties. And it is! But once you encode rules, you can start eroding them. Every new concession tender going out, you can try to dilute such conditions. A bit is enough - every step gained can be relied upon in future negotiations ("you're asking for more than last term"). And, of course, every small step can be argued by increasing costs - because cost will always increase anyway.
The TL;DRR (didn't read the rant): the public commons has a tendency to erode in favour of privatisation. There is pressure to do so, and no real counterpressure to reverse, only to not go too fast.