Hi. I apologize in advance about doing a drive-by posting. This thread came up in my Google Alerts and I thought I might be able to be of some help. Moderators, feel free to delete this if it violates local norms.
Every photo that is released into the world - published, distributed, or whatever, should be labeled ("on the back of the print" as it were) with what the photo depicts, who made it, and who owns the copyright. You'd think that would be kind of obvious, but given the number of images wandering around out there like the Paddington Bear, apparently not. And then there's the whole matter f finding a given photo in your collection a decade from now. Without decent labels, that won't be fun.
Where in the workflow one adds that information is an open question (And I presume the point of this thread) Could be in the beginning, at the end, in your main editing application or something else, or a combination thereof.
I would think that an application that aims to provide an all-in-one workflow - a "Lightroom killer" - should feel more or less obligated to provide reasonable metadata tools, which would include read-write support for a well chosen subset of the IPTC fields, and tools for users to efficiently use them. (And that's not a trivial task. The standards are, well, Bizantine on a good day.)
It is true that many websites strip away metadata. That's bad. But others' bad behavior shouldn't prevent us from doing our part.
Insist that any software solutions that you use embed information according to industry standards, so that you don't lose your work if you use a different application later. I've seen applications that have keywording or tagging functions that don't put the tags where they belong in the embedded metadata. That's a sleazy lock-in tactic that should be avoided at all costs.
I do a blog on metadata and there's a fair bit of information there that may be helpful for your considerations. carlseibert.com/metadata The post at https://www.carlseibert.com/metadata-protects-photographers-work/ is a photographer-oriented introduction to some of the issues, and may be a good place to start. As I remember, it included a mention of Copyright Management Information and what it means to photographers. And there was more on that topic in the introductory post for webmasters. I'll check back with this thread later, or you can always reach me through the contact button on my site.
I hope this was more help than noise.