You are making some strong statements.
I think it's fair to say that Obama was much more trusted in Europe than either Bush or Trump. When you break it down by country the story is more complex, but the poster did admit to being western European.
The breakdown of the (hidden) alliance the US media had with American politics to now open hostility could make that harder, because it is visible worldwide. Again, the media could turn it around, if it wanted to. But it feels unlikely, they will with Trump. So the best chance for reconciliation between the fourth power and the government is a democratic win in the upcoming election.
Fair or not fair, it seems from an outside perspective that if Trump wins again, all hell could break lose in the US. There could be a civil war anarchy vs. authority.
I think there are some things amoung Trumps policies, that if people were a little more honest have been attractive even to the left of some or even most of the other western nations, like putting more value on local labor.
The problem is less about opinions and more a concern that a 'lapse' on US part to care for democracy and freedom worldwide (even if it might not always have been genuine in the past either), openly speaking more positive about some more authoritarian leaders than democratic leaders, etc. could have the more long lasting negative effect on the world.
If you listened to the media the US has the worst virus response in the world. Obviously that's not true: https://coronavirus.jhu.edu/data/mortality
But you would not know it by reading the news.
The US has, for the most part, extensive resources with which a global pandemic can be managed. It has money, people, manufacturing capability, research centres, and medical facilities. But the country has catastrophically mismanaged this challenge, and this is almost entirely for political reasons. Over 100k people are dead – it's a bad outcome, and we should be looking at why that bad outcome happened and what can be done to fix it.
I live in the UK – another country which has also badly mismanaged this pandemic. The reasons are a little bit different, but it does seem pretty startlingly obvious to be that the underlying problem is the same – you cannot solve a real-world problem by pretending it does not exist. The UK failed its response because it spent too much time on political management and lying to itself, and not enough time on dealing with problems and being honest about them. The same applies to the US, and it's honestly absolutely breathtaking the number of perspectives I have seen that want to apologise for this.
Belgium, UK, Spain, Italy, Sweden, France
At the rate we're going, that may change eventually, but when you compare the general discussion of, say, the US vs. Sweden, it's obvious there is an absurd amount of bias, both from the US domestic media and others.
Basically: The US has not actually changed, but the Media really really really hates Trump, and Trump really knows how to say stupid things, which gives them lots of ammo.
They would do well to ignore most of what he says, but they can't help it: He sells lots of clicks.
Out here in the real world the US is not actually doing bad, the US response to the virus is not actually really bad (it's inline with other countries see: https://coronavirus.jhu.edu/data/mortality ).
This is basically just media desperate for clicks to sell ads. And they don't care about the collateral damage. (See my other post in this thread for more details about how this NYT article is a perfect example of the media badly representing things.)