When placing a file using File>Place Linked... there should be an option to not store any pixel data of that Linked file into the PSD file to keep the file size as small as possible.
For example: When I take a bracket shot with my drone (DJI Air 3) in 8K, each of the RAW photos (DNG) is about 100MB in file size. When I now import 3 of these DNG files into Photoshop using File>Place Linked... and just save it as a PSD, the total file size is 792MB which is absurd in my opinion considering that each RAW photo is only 100MB.
When I do exactly the same by using File>Place Embedded... and save it again, the PSD file size increases to 1,98GB (which is completely insane by the way).
So there is definitely a benefit of using the Place Linked... option but it's still pretty clearly saving a large amount of pixel data into the PSD file even though I set Image Previews and Maximize PSD Compatibility both to Never under the Settings>File Handling tab. My file explorer (macOS) also doesn't show any previews or thumbnails for those PSD files, so I really don't understand what makes the PSD files so huge.
In my opinion a Linked file should work similar as it does in Lightroom Classic and only store the Camera RAW settings of each linked RAW file and then create the actual image when opening the file in Photoshop and store it temporally in the RAM or the Scratch Disk.
I actually discovered an interesting hack/workaround for this problem which doesn't make any sense but it definitely works:
The trick is to change the Image Size within Photoshop from originally 8064 pixel down to 80 pixel and then save again. This alone decreased my file size from 792MB to only 134KB!!! That's a massive reduction in file size of 591000%!!!
Once you open your PSD file back up again you can just increase the Image Size from 80px up to 8064px again without loosing any image quality since all the photos are Linked files.
The same trick also works with Embedded Smart Objects but only reduced the file size in my example by 40% from 1,98GB to 1,19GB which is still a lot!
Of course this hack doesn't work if you have other pixelated layers or masks in the same file but in that case you can just scale down each Linked layer individually and then change the Canvas Size to 80 pixel again. If you have masks applied to the Linked layers, you can just move the masks to new empty layers before scaling down the Linked images to keep the masks in its original size.
This will still drastically decrease the PSD file size, for example my file with 3 Linked RAW images and 1 mask went from before 826MB to only 28MB since Photoshop only has to store the pixel data of the mask now in the file.
Of course you have to scale everything back up again and reapply all the masks when you open the PSD file later but this could still be a good workaround if you just want to keep the files as backup and store them on your hard drive without taking up an unnecessary amount of space without loosing any quality.
Another huge benefit of doing this is the time it takes to save and open those compressed files. For comparison: the 792MB file takes over 30 seconds to save on my Mac Studio M2 Max which is already a very fast and powerful machine.
The scaled down 134KB version basically saves and opens within 1 second. So it's actually faster to open the small file and scale it back up then opening the large file!!! especially when you create an Action for scaling up & down the File Size.
That's why I think this should be the standard behaviour of Linked files within Photoshop or at least give us the option to NOT save any pixel data of Linked files to keep the file size as small as possible so we don't have to do these tedious & unnecessary workarounds anymore!
This would actually make the Place>Linked... feature much more useful for many users!