According to a report from leading malware prevention company Malwarebytes, "The average number of [malware] threats detected on a Mac is not only on the rise, but has surpassed Windows—by a great deal.". That does sound like something worth worrying about if you're a Mac user.
It rightly guesses that this increase is likely due iin part to the increased popularity of these devices, meaning they make a more attractive target for attackers. However, it goes on to suggest that "macOS’ built-in security systems have not cracked down on adware and PUPs to the same degree that they have malware". While this is also true, within that jargon are hints that the problem isn't quite as serious as it might seem at first glance.
"Malware" is often used as a catch-all term to refer to all sorts of nasty bits of code that can end up on your device. However, as a catch-all term, it naturally covers a wide spectrum of seriousness. At one end, you have the sort of malware that destroys your files or demands ransoms. At the other end, you have adware which is more of a nuisance - tracking browsing habits and flinging unwanted ads at the user.
Also, it should be noted that this research has been produced by a company whose business is selling malware prevention software. That's not to say that it should be discounted - they are in the best position to be making the observations needed to collect this data. However, it's worth just bearing this in mind when considering the motivation for these findings.
So, does that mean that Mac users don't need to worry about this? Well, no. Historically, Mac users have had it easy in the malware department. This is partly due to the differences between how the operating system works compared to how Windows works. However, it is likely that the bigger factor here is the userbase. From an attacker's perspective, you want to target as many people as possible with the smallest amount of effort. If everyone is using Windows, then that is where you are going to concentrate your resources.
However, as people move to other operating systems (and devices - this is also becoming an increasing problem on mobile devices), the range of malware is adapting accordingly. The advice remains the same though. Always be vigilant, use strong passwords that are unique to each application. and don't click on any links you're not expecting.