You are singing my song AlfaQ. Early in my adventure I came upon a minimizing brassiere from Bali and it has been my favorite ever since. If you've looked at photos I've posted you likely saw one or another of those brassieres. I'll drop a triptych in at the bottom of this post.
One feature that contributes to the name of these brassieres is that they don't have any sort of padding, even the thin layer that creates the cup shape for every T shirt brassiere. In addition, as you note, the cups don't have stitching of any kind. The cup material is designed to create an appealing shape while constraining the breasts. Some men are concerned about their nipples showing. That has been discussed on these threads at different times.
This style brassiere is the one I wear most often. It doesn't hide my breasts but it does a lovely job of constraining.
Here is a link to this particular brassiere.
https://www.herroom.com/lilyette-0904-plunge-into-comfort-keyhole-minimizer-bra.html