Overwrite master/original photo with current modified version & reset change history

"BUT there are times I would like a way to OVERWRITE that original image to be THE MODIFIED photo"

And thereby lose the RAW file.

Terrible idea, and utterly contrary to the whole point of shooting RAW and using a non-destructive RAW converter like LightRoom.

"I believe the user should be the one to decide if the edited/adjusted image is worthy of overwriting the ORIGINAL and losing the change history, and this feature should be available within the product"

In another post, you ask for the ability to be able to recover files that a user has deleted, because of the risk of "accidental" deletion in LightRoom: seems to me you're admitting that leaving decisions to users isn't always a smart idea.

But - again - the entire fundamental principle of shooting RAW is that the original file remains untouched. And that's as it should be. 

If you really want to do all this overwriting, Lightroom Classic is not the tool for you.

Such a feature would also make those images available to other software/apps on the same device/network without the need to export and duplicate images (e.g. screensavers, etc).  It would also save space.

By @MarineGirl405

Part of the problem is that it might or might not save space. It might work if all your images are TIFF or Photoshop files. But with raw files, it’s different. Currently, you could have a 20MB raw file and a few KB of edit metadata. The edits can never ever, ever, update the original raw file, by any software you can find, by any company. Because raw files are read-only. That’s why permanently applying edits to a raw file always requires exporting a copy, in any software.

So then you could have Lightroom Classic add a feature that would replace a raw file with a TIFF or Photoshop copy containing all the edits. But then you have another problem. The file is many times larger…you don’t save any space, in fact you lose space. That’s because a raw file is just one data stream, while a color TIFF or Photoshop file is multi-channel (three RGB or four CMYK channels), causing the file size to at least triple, and it can go even higher depending on the features used. You save a lot more space saving 1000 raw files with edit metadata, compared to the same images replaced with 1000 images rendered to TIFF replacements.

Another (of the many, many) problems with the idea is that you might not achieve your goal of one image to serve all purposes, to save space. For that to be true, all of the uses have to support whatever the one stored file format is. For example, if you want to replace everything with TIFF format images, but you want to submit images to a competition or upload to a web page and they require JPEG format images only, you have to make JPEG copies anyway.

You could just say replace everything with JPEGs, but because JPEG is a lossy compression format, it may severely limit the ability to re-edit for future uses. And if a major reason to replace everything with JPEG is to save space, a better way to do that is use the feature already built into Lightroom Classic that can replace everything with lossy DNG, which is not subject to the same limitations as JPEG, or at least not as much.

In the end, when you consider the full scope of how images might be used, and the storage and quality consequences of replacing everything with rendered image formats, the simplest and most flexible way to preserve both quality and options is still to maintain originals with edits separately, then only merge them to exported copies when there is a specific need. Which is the way Lightroom Classic already works.

Lightroom is a parametric editor, and all edits are stored as metadata. The original pixel data are never overwritten. That's just how Lightroom works.

You can Export the file with all the edits baked in, and delete the original. If the original is a raw file, this will throw away a lot of data in rendering the raw data into a gamma encoded RGB file. This is irreversible destruction and not recommended.