It's only when a subject becomes popular that the propaganda gets recognized and rectified.
A lot of wiki pages about smaller companies only list the good things (fundraising, tech, etc.) and omit any controversies. The deliberate omissions due to bias are even more insidious than weasel words or other forms of poor journalism.
Fwiw I truly believe in Wikipedia and donate every year, but calling it "perfect" would be extremely dangerous (and false!)
* A sketchy online university that was clearly manipulating their Wikipedia page with lots of positive information about themselves to suppress info about their active lawsuits and controversies
* On medical topics: non scientific, baseless claims about the efficacy of various herbal treatments, vitamin supplements, or other snake oil treatments.
* On various fringe politicians. Someone clearly rewrites the article or adds additional things to the article with claims about what the politician has done or not done or wants to do, but these claims are arguably not fact based.
Now these things usually don't last for a long time. They do get rolled back or removed. But it doesn't have to be on there long for it to be utilized. For example, someone just needs to modify the Wikipedia page long enough to get through their active lawsuits, or the snake oil salesman just needs their info up on Wikipedia for long enough to use it to increase their perceived authenticity to trick some seniors. There is such a constant stream of bad actors trying to put this stuff out there that you'll see it eventually, and it doesn't even have to be up there for long for it to be harmful.
So I re-read the entire page, this time looking for signs it was written by marketing rather as a factual document. Of course it was exactly that. Only the engineers deep in the bowels of the organisations developing 5G knew how it would perform at that stage, and evidently they weren't contributing to Wikipedia. Until the man on the street had experience with 5G, the marketing people were going to use the Wikipedia page on it as an advertising platform.
So I'm in agreement with the OP. From what what I can see a Wikipedia page that only has a few contributors it is no better than any other page about the same subject on the internet. The breath and depth of a Wikipedia page on a subject arises because of the wisdom of the crowds contributing to it. If there is no crowd, it's possible there is no wisdom.
Fortunately Wikipedia does have one other advantage over a random Internet page - you can tell when the have been lots of contributions. There is an audit trail of changes, and you can get a feel for the contentious points by reading the Talk page. That contrasts to getting the same information from an LLM, where you have no idea if you are being bullshitted.
As you might predict from all that, the Wikipedia page on 5G is very good now.
In general, it is not uncommon to come across slantedness issues. Is it completely 100% clear that Doi has come on and maliciously added his papers? Not quite, but good propaganda wouldn't be either, and would actually be far less suspicious-looking.
Russia is the major player in pushing disinformation in historical articles about eastern europe (and not only). It works on it systematically by using both hired editors and volunteers on scale as well as producing “backing” materials.
Framing editors who are trying to keep up with cleaning all this mess as bad actors is understandable if you support the goal why russia is doing that.
But, its by far the best human-averaged source of info on most topics. I'd say even politically charged topics, definitely much better than most news out there who always show some clear bias.
Its not exhaustive (another common complain form folks who seek visibility by complaining and denigrating stuff for the heck of it or some immature popularity), its not meant to be. You also don't do postgrad level physics studies from Encyclopædia Britannica, do you, but it may give you some shallow introduction to orientate in the field a bit.
Thankfully one of the primary vendors (Qualcomm?) had really good doco publicly available.
It even included a lovely diagram showing which frequencies were useful in different scenarios. And a list of likely allocations per country. Letting me create a nice side by side of possible 5g strengths in Australia vs the USA.
You'll see "xy atrocity had caused the deaths of this many people*", where the additional note will say something like "The numbers reported in this study have been challenged by many scholars on the subject and has been accused of invalid methods".
It's super common with history around Communist countries, because for a lot of folks in the west, the black book of communism is taken as fact when it's far from it, and you have groups like the Victims of Communism memorial foundation that have huge coffers for pushing the black book line.
Just because we don't enumerate Wikipedia's faults doesn't mean we think it's perfect.