Because apparently none of the developers have the need for it, and other people are just waiting or something.
It comes back to the expectation of opensource development.
A question ‘why is it taking so long’ seems to imply that
- it’s easy
- the developers that are active agree with your priority assessment
- they the time having past is indeed 'a long time '.
The basic rule to remember - always - is that the programs are developed how the devs want them to be. Not how you think they should be. That doesn’t mean it needs to support the latest and greatest , it doesn’t mean it needs to compete with other software , and it doesn’t mean that an ‘obvious’ feature for you is put up high in the list.
Personally , the statement ‘canon has been the leading camera maker for the past decade’ made me giggle. They finally caught up is how I see it, but ok.
But the question of new file formats affect all manufacturers, so it doesn’t even matter.
Edit: I think I’m confusing Darktable and Rawtherapee things in the story down here, but the principle still stands. I believe it was Darktable using exiv2, why Cr3 support in Darktable took a while. Rawtherapee uses exiftool , and I don’t know the state there. But the principle is the same, all the dependencies need to aligned and need to be used in a build to get something working.
In the case of Cr3 - i believe, I didn’t follow it with much attention because I don’t care about Cr3 - is that the ‘base’ format which contains the data is based on more recent container formats. So, it isn’t “like a TIFF file but with raw data” but it is more “like a MP4/mov file but with raw data”. That means metadata is written in another way.
Now, the thing is, that there were some questions and observations about that base format having certain patents or copyrights around it , that made the authors of metadata libraries be careful about wanting to implement it. Which is of course fully in their control.
And the exiv2 library is used by Rawtherapee (or was it Darktable?) to read and parse information about the files it opens.
Now, there has been support here and there. I believe other programs like art and/or Darktable made an exception for Cr3 files to not use exiv2 for just Cr3 files… or they changed to another metadata system all together. I really don’t know .
I believe exiv2 has even the correct support added ? But that would mean you would need a recent build of Rawtherapee, that was build using a recent version of exiv2, and probably a build of exiv2 that had the special support enabled (which might not be the case by default ).
So that are a lot or maybes that affect if Rawtherapee is now able to read Cr3 files or not .
Or they just left it at reading the raw data and not bothering with metadata, who knows .
The common answer to 'why is this obvious feature taking so long ’ is that the feature isn’t as obvious as you might think , or the devs have very little time, and relative simple stuff takes a lot of time.
Very often a combination.
If i was developing software to use myself, feature requests for a file format which is of no relevance to me won’t be high on the todo list.