Rule of thumb IMO. This is NOT legal advice. Just my opinion on what is morally right.
If you think the relevant parties wouldn’t mind, then obviously they wouldn’t mind!
If you think they WOULD mind, then it is not right IMO unless you feel there’s something inherently unjust about the system.
For some anime communities, they post stuff and some companies don’t mind it and actually let the anime community know if they are about to make a release outside of Japan and the anime community complies with their wish and stops sharing and making subtitles. I’ve read that this has been changing for some companies now though.
I don’t watch anime myself; just something I read.
Here’s a clear cut case where they wouldn’t mind IMO. If a homeless man or destitute woman listens to pirated music, the record companies IMO wouldn’t mind since she wouldn’t be able to afford their music anyway.
But if you are able to afford a computer and internet, then the only way to justify it IMO is to say there’s inherent unfairness or something like that.