I agree. Sometimes, implying that you understand can be disastrous. For example, if you say that to someone who is suicidal, things could go really bad.
For tough situations, you can try saying “I can only imagine what it must be like” and even tell them you can’t understand. But you are still being supportive, you are still establishing rapport, which is important if you want to communicate.
I’ve seen this taught in crisis counselor training.
Whether methods like these are manipulative is something you might have to decide in the moment. But it’s a lot safer than say, taking control over someone empathically and controlling their emotions, images, thoughts, etc. That’s a lot more ethically risky and is usually only good for helping others in certain situations. Use it the wrong way and you’ll learn about how Karma works.
But with more simple communication techniques, I wouldn’t stress out about it too much. Listen to what your gut is telling you.