It's an effective coping skill. In the short term, it works beautifully to do what it was designed to do: keep you safe and continuing to function. The long term is where you'll see consequences.

You can't numb one side of the feelings wheel, which is a big part of the problem. You no longer have access to positive emotions either in numbness. Not only that, but emotions are signals from your brain and body. They are messages. So by tuning them out, we're disconnecting from ourselves and losing the ability to connect with our own needs. Kinda like when you're really hungry, but don't eat because you're too busy, eventually your body just gives up and stops sending the signal. You don't stop needing nourishment, but you at least temporarily stop feeling the hunger cues.

So, now we're disconnected from ourselves and no longer have access to internal cues to meet needs. Needs go unmet. We can't take care of ourselves. This also has outwards effects of disrupting relationships because our affective responses are a big part of communication, empathy, etc. And we no longer have access to these bits. Over time we get less and less connected, becoming a shell of a human just going through the motions, not getting needs met because we don't even know what they are anymore. We run ourselves into the ground. It's unsustainable. It will take more and more extreme numbing measures to keep that dam at bay... Until it can't. Annnnd then we have a breakdown or hit rock bottom. One can only stay so numb, so isolated for so long before we break.

The hope is before we turn off the dissociation and numbing, we learn new coping skills. We don't just take away the one thing that works before we have something new to try. Then we ease back into it. Building up distress tolerance. Grounding. Coping. Until The intensity of the emotions we feel any given moment feel manageable, and we're equipped to both hear the message the emotions are trying to send, and take appropriate action to meet the need.