I can understand setting aside time to not get on HN or twitter, but how does a developer keep up without these? As in, work on a needed library for weeks only

I can understand setting aside time to not get on HN or twitter, but how does a developer keep up without these? As in, work on a needed library for weeks only to find out later that there's a good open source one that meets your needs? Or just be alerted to alternatives to investigate, like PyTorch vs. TensorFlow?