Because technically, it's a scanner + printer and not a mover. It's just that the original is deliberately destroyed every time (unless something goes wrong *looks at Miles*).

IIRC, it's even mentioned that people going through the transporter are cached. Like, they store snapshots, so you can compare the changes between older you and newer you. You can also store a person in buffer digitally, meaning you can copy and print as many as you want.

Why do you say it’s a suicide if you never saw or felt anything, and you manage to say around somewhere afterwards?

Because you are killed, and society gets to keep running with a photocopy of you. From an external perspective, you move from a to b. From your perspective, you die.