How old is too old for Halloween?

I wasn't really sure if this should go here or in The Quiet Place. So.. if it's in the wrong place let me know..

Since it's getting closer to Halloween my sister started getting ready to go trick or treating. But she is getting a bit old now (16). So I became curious about this subject. I talked with some of my friends and family about the ages they stoped going trick or treating. What ages they started going to parties and even when they stoped doing those.

I got a lot of varied responses for when to stop trick or treating. From as early as 13 to as late as 25. Most of them stopped around 17-19. But a few of them still do it to this day and they're ~20.

The majority of them started doing parties in their late teens. But only a couple stopped going to them once they got into their 20s.

I also noticed the younger ones who dont do either stated that if any one 15 and up came to their door for candy they would turn them away. While those who still trick or treat or go to parties in their older ages would have no problem with an older teen coming for candy as long as they put some thought into their costume.

So I ask you GFF, when did you stop? Do you think it's okay for those older people to do it? Would you rather party or go get some free candy?

How ya doing, buddy?