The key points are:
The combination of the natural human tendency to focus on bad news, expectations rising beyond the ability of the economy to deliver, the increased availability of information & the rise of social media are likely magnifying perceptions around worries and making it easier to be gloomy.
However, to succeed as an investor it makes sense to err on the side of cautious optimism: otherwise, there is no point in investing; growth assets like shares have trended up over the long term; and trying to get the timing right of the 2 or 3 years out of 10 when they fall can be very hard.