In what situation is she better than reaper?

I started playing in season 1, skipped season 2, and came back in season 3. I'm platinum on both support and dps, so yes this is a METAL RANK QUESTION. I don't have a specific main, I am a counterpicker, and i usually pick anran when i want to dive the enemy backline.

Recently, I tried reaper, and wow, he just feels like anran but much better in almost everything. His damage is like anran's right click when enemies are burning, can actually sneak into the enemy backline without anyone noticing, can even fight tanks effectively, and doesn't even have to aim.

The only situation where anran seems a little better is if my team has mauga and ashe, and the enemy team doesn't have kiriko, i guess you could say her ult is better too if the enemy has a brain.

I don't get why people always compare her to genji when reaper is right there, anran and reaper has to be in the enemies face to do something, unlike genji who only go in when he poke enough to dash and kill someone (or ult obv).

So, in what situations is anran actually better than raper? Or am i just wrong in everything here?