[antasvara]

No different from applying to jobs. Much like companies, there are a variety of journals with varying levels of prestige or that fit your paper better/worse. You don't know in advance which journals will respond to your paper, which ones just received submissions similar to yours, etc.

Plus, the t in me from submission to acceptance/rejection can be long. For cutting edge science, you can't really afford to wait to hear back before applying to another journal.

All this to say that spamming 1,000 journals with a submission is bad, but submitting to the journals in your field that are at least decent fits for your paper is good practice.