Bond ETF: basic question

Hello,

I am interested in buying Bond ETFs as from what I am reading and hearing they are considered "safer" than stocks. However, I noticed that some of the ones I am interested in suffered a -8/-14% average price decrease in the past 10 years.

Now, how can these be considered interesting investments? I assume this would be because of the coupon yields, but how can I make sure/track that these offset the losses due to the price reductions? How does it work?

Thank you!