People often think that things like recording your screen or keylogging are the worst but they're not. These attacks would require you to be targeted by someone looking for something specific.

Meanwhile automated attacks can copy all your files, or encrypt them (ransomware), search for sensitive information, or use your hardware for bad things (crypto mining, spam, DDoS, spreading the malware further), or most likely all of the above.

Automated attacks are much more dangerous and pervasive because they are conducted at massive scale. Bots scan massive amounts of IPs and try all the known exploits and vulnerabilities without getting tired, without caring how daunting it may be, without even caring if they're trying the right vulnerability against the right kind of OS or app. They just spray everything and see what sticks.

You're thousands of times more likely to be caught by such malware than it is to be targeted by someone with the skill and motive to record your screen or your keyboard.

Secondly, if someone like that targets you and has access to your user account, Wayland won't stop them. They can gain access to your root account, they can install elevated spyware, they can patch Wayland and so on.

What Wayland is doing is the equivalent of asking you to wear a motorcycle helmet 24/7, just in case you slip on some spilled juice, or a flower pot falls on your head, or the bus you're in crashes. All those things are possible and the helmet would come in handy but are they likely? We don't do it because it's not, and it would be a major inconvenience.