100% there will be more malware and scams as Linux grows. In fact, it’s happening already.
Just look at there being multiple instances of cryptowallet theft on Ubuntu’s app store by devs uploading fake copies of crypto wallet managers.
And that’s before we even get onto DEs – and much of the desktop Linux stack in general – generally not being designed with security in mind, as it’s not been something they’ve had to worry about.
We will see more malware, more scams. We will see glaring security problems that were allowed to stay in place for years be exploited. We will see infighting in the Linux community over all of this stuff.
It is the price we must pay for being an increasingly relevant platform.
With any luck, more users will mean more contributors, more financial support for devs, and of course better security as a result of that - you only need to look at how much KDE Plasma has improved with support from Valve, and how much work Gnome has been getting done after Germany’s “Sovereign Tech Fund” contribution to see that even a little bit of support can go a long way.