Of course, you could always try SciDB, a continuation of SciHub, hosted at Anna's Archive. I would think there aren't legal concerns if you're just looking at the title, but I am Not A Lawyer.
I was picturing it as a sort of 'Here's a new paper' feed, but obviously if you're getting 5.2 notifications per minute even the interesting stuff will get drowned out. Am I envisioning this wrong?
I don’t know if this is compatible with your use case, but as a working scientist interested in my sub field and those adjacent, I subscribe to email alerts from publishers (all nonprofit scientific societies with the exception of Nature). There are both table of contents emails and keyword-based emails. Not sure if RSS feeds are available. If you’re wanting to do some automated parsing, you might need a dedicated email address (and of course access through a university library or similar).
According to Science [https://www.science.org/content/article/scienceadviser-scien...] there are about 2.82 million articles coming out every year. That's 5.3 papers every minute, 24/7.
If you mean a list of titles, your best bet would probably be something like https://www.ncbi.nlm.nih.gov/pmc/ [PMC, life sciences/medicine], https://www.jstor.org/ [JSTOR, general], https://scholar.google.com [general], https://scholar.archive.org/ [from the Internet Archive; I haven't used it much, but it could be helpful if the journal is now defunct]. There are others, like the ones on this list [https://blog.scholasticahq.com/post/index-types-for-academic...]. I'm not sure how much overlap there is between those.
Of course, you could always try SciDB, a continuation of SciHub, hosted at Anna's Archive. I would think there aren't legal concerns if you're just looking at the title, but I am Not A Lawyer.