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