I completely disagree. Either we remain under lockdown restrictions forever, which is farcical and unliveable, or we learn to live with the virus in which case the virus needs to burn itself out, or learnt to be lived with.
The vaccine rollout is done effectively, the very few hospitalisations that are occuring are almost entirely concentrated within the tiny minority who have refused the vaccine. What are we supposed to do - keep restrictions in place forever to protect antivaxxers?
We're pretty close to herd immunity and the virus is just filling in the gaps where people haven't taken the vaccine, or aren't eligible for it (children). After that it will be over and burnt out as the virus smashes into a wall of vaccine-created herd immunity once it runs out of others to infect.
With respect the flaw in your logic is that there isn't an infinite pool of people for the virus to infect, so no it won't eventually eliminate the effectiveness since the virus will be burnt out before that happens.
If the virus isn't causing deaths or hospitalisations eventually we need to stop testing and panicking over this and just live with it like we do the flu and if it spreads, it spreads.
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Another way of looking at it is that if a novel virus had arrived in normal circumstances with our post-vaccine infectiousness, hospitalisations and deaths as the default unvaccinated rate would we have ever locked down in the first place? No, we wouldn't. It would have just been considered like the flu and not been this pandemic. Actually fewer people are dying from this than the flu, post-vaccination this disease is less deadly than the flu. If the link between cases and hospitalisations/deaths has been broken then its time to stop worrying about cases.