They don't even need to force it. Every ISP in Russia has government-managed DPI hardware that filters all use traffic performs such blocking. No cooperation from ISPs is necessary.

I guess it's worth it when the other option is to basically become a state controlled tool that doesn't offer any good for the Russian people.

I’m more worried that this will give malicious non-state actors and, worse still, the Russian government easier access to Russian citizens seeking the ability to look behind the veil. The result of this repression will be inexperienced folks downloading an exe and quietly being logged as a dissident or innocent people finding their information compromised or hardware hijacked. Sourcing clean, difficult to track downloads of these addons and Firefox will become important in the near future.