Doppler or not?

[Apple35]

What are people's thought regarding buying a doppler? Good idea or not?

This is Tommy’s advice (a charity for miscarriages/stillbirths), I take everything they say as gospel....
www.tommys.org/pregnancy-information/about-us/tommys-midwives-blog/word-us-home-dopplers

I asked my midwife about them during first pregnancy and she said if you saw someone collapsed in the street you wouldn’t just go and check for a heartbeat and then move on if they had one. E.g if you are concerned about the baby enough to put the doppler on (reduced movements for example) then the presence of a heartbeat is not enough to indicate that the baby is well, just alive at that point. It was enough for me to never consider again and sign a petition online to get them banned from being sold