There are people who genuinely care and those ones want to know your feelings, help with supports and leads to get you back working. But most coworkers are just bored with their lives and are looking for things to talk about. "What happened, what did they say, what did you say?" I actually cut those people out fast.

They hate their jobs too and want to know how you made a successful escape!

No to be a jerk, but anyone flaunting their "amazing" lives right now is not really living in reality.
Travel Vacations, child care, education, concerts, sports, etc are all off the table for everyone...
but go on how you and only you are living the greatest life in these times.

a) They may be concerned for your well-being and just wanting to make sure everything is okay.

b) If the workplace is particularly shitty and toxic, they may be reaching out to get confirmation on harassment or injustices committed by particular people to build a case, arm themselves against such behaviour, or obtain that extra bit of courage to do as you did and leave.

In any case, it is their right to reach out and your right to decline comment.

So why not simply say politely that you found a good opportunity elsewhere, instead of getting all hot and bothered about it.

You seem nice (joking).

Have you thought of changing your number or blocking them?

It never ends up well for cowards who stick their Pinocchio noses where they don't belong.