These answers probably won’t be very encouraging but here:
1. I don’t think there’s anywhere to be honest. Not many people have, let alone carry around a 3DS anymore
2. Ties into the last point
3. Wouldn’t be able to tell you since I haven’t gotten a Streetpass since the eShop closed
What others have said is entirely true. I've heard of a few people bringing their 3ds to conventions, game stores, specific streetpass meetups and the like to get a few tags, but it must still be pretty rare.
I'm pretty sure that most streetpass titles would work the pretty much same as they used to, since streetpass is a local wireless feature. But i'm sure that the streetpass mii plaza puzzle pieces don't rotate anymore, and you can't buy the streetpass add-ons from the eshop.
I stopped carrying mine before Online shutdown. The only tags I got was from my other 3DS.
2023 Youtuber visited NYC during Comic Con and was able to get 9 tags. 6 from the Comic Con and 3 from the Nintendo Store in NYC.
If you have an extra 3DS you can tag your consoles every 8 hours. I was able to complete 3 players Animal Crossing New Leaf streetpass badges.
Agreed with other people that it’s rare to find others nowadays, but there are some places you’ll have more luck at.
Bring your 3DS to large gathering of “nerdy” things (eg various conventions) are more likely to have people.
Also, if you mod your 3DS to have Pretendo (which allows you to play 3DS games online through a private server) o you can supposedly Streetpass the friends you have through it!
I like streetpass and sometimes still carry my 3DS. It still works. I often get streetpasses at conventions. And occasionally at other crowded places. Most days I get none though. According to mii plaza I have 3076 tags.
