This doesn't seem to be a problem with snap. Canonical probably tried to show vendors a way how to distribute software commercially. But vendors are on the level of cavemen and don't know shit about Linux even after serving a solution. Or they simply don't care about building up a market opportunity.
I don't want to defend Ubuntu. I don't like Ubuntu especially, but it might be a simple explanation.
You should notice that I use the word "trust". I install stuff on my servers and PCs from people who I trust. Why should I trust someone who makes an anticheat engine. Why should I have a reason to do that?
You should also understand that a kernel-level piece of code that can be updated is a very good rootkit. It contains all essential tools to modify hardware, kernel, install drivers, keyloggers etc. It satisfies the definition of "rootkit" very well.
One single piece of code is enough to be a rootkit.
Rootkits: The rootkit is considered to be a type of Trojan horse. Many Trojan horses exhibit the characteristics of a rootkit. The main difference is that rootkits actively conceal themselves in a system and also typically provide the hacker with administrator rights.
If you compromise your system with software that you don't know and potentially can introduce a backdoor (even involuntary via bugs), you have a rootkit installed.
If you don't trust it, don't install it with admin privileges. Maybe don't install it at all. Anticheat is a shady business. And mostly not owned by the company that produces the maybe trusted product to be protected.
Usually, they can, if there are risk of violence appearing. You're allowed to protest peacefully, but the current situation suggests the protest would be based on anger and maybe provocation.