Keep in mind that, so far, the vaccines have been effective against all of the variants that have popped up. It is certainly possible that the virus mutates into a variant that isn't controlled by the vaccine. But it's also possible that even if we continue to have variants, the vaccine will work just fine against them. Variants rendering vaccines ineffective isn't a guarantee, even if we don't get the percentage of vaccinations we would like.
I agree. It’s very low risk and community spread is dropping every day so getting lower. The less people spreading the virus the less chance of breakthrough infection too.
It's not just "possible" that the virus will mutate, or that we'll have variants. Both of those are definitive. The virus WILL mutate, we WILL have variants. Most of those mutations and variants will be less competitive than the dominate strain circulating and will disappear, we'll never even hear about them, they'll just disappear.
In the shorter term, variants the vaccine is less effective against definitely are NOT a guarantee, as you said. It's like the virus is playing the lottery and it keeps losing, which is good for us. Get community spread low enough, and there will not be enough lottery tickets for the virus to ever win. That's the concern with not getting spread low enough if we don't vaccinate enough, it's like we're handing out free scratch offs to the virus. Hand out enough of them, and it's chances of winning increase. Vaccinate enough and this problem goes away.
I don't worry about a variant getting past the vaccine on any large scale today. I worry about us taking actions that encourage that outcome over time. Just like handing out antibiotics like candy has left us with antibiotic resistant bacteria to deal with. Or, lice resistant to the tradition chemical remedies.