It's more about getting chastised and guilt-tripped about refusing to go yet another holiday family event where multiple people are likely symptomatic and they get mad you opt out, then you're vindicated later when many people actually get sick

not the op, but i would assume that some of the participants were already verifiably sick before the event...

People will go to family gatherings even if they're sick, and hide that they are, because faaaaamily. Also, children are little disease factories.

Some vaccines don't really guarantee anything beyond reducing your chance of ending up in a hospital (and they can be less good even at that if the particular strain that you get isn't the one you were vaccinated for.) For some vaccines, even vaccinated, you can still get the disease you're vaccinated for and have anything from a couple weeks of being sick to life-long debilitating effects.

All else being equal, unless you have some particular reason why you're not a good candidate for a particular vaccine, the significant majority of people are much better off vaccinated than unvaccinated, but vaccinated doesn't necessarily mean safe to go lick doorknobs or, case in point, dine with a dozen relatives, whether those relatives are vaccinated or not. And of course there are plenty of reasons why OP might be at higher risk than most.

Where I am, children under 12 have not been vaccinated against Covid since their first so no annual vax. Last shot was start of 2022 so has waned considerably.

That's like wearing sunscreen and then sitting under a UV lamp all day. It's better obviously, but still not a great idea.

vaccines do not work that way

That's Herman Cain - Tea Party activist and businessman active in politics. He famously died after contracting Covid from an indoor political rally in Tulsa at the height of the pandemic before any vaccine was available. E: fixed typo in his name