There are print on demand reprints of public domain works, via Amazon's Create Space platform. However, the economics of Print on Demand leave you with a much higher unit price. I deal with this all of the time, when family members want to reprint a family cookbook, then find out it will cost about $300 for 4 or 5 copies. Commercial printing spreads the cost out over the entire print run. Print on demand means you have higher unit costs, which means the consumer has to fork up more money than a commercial book, for you to make any money. Then, you have the question of who is doing the printing. If you are, you have to figure in the cost of maintaining your printer and other hardware, including your computer. Laser printers use toner, which is way more expensive than ink, though it is more economical for high volume printing. If you are using a commercial print shop, you have to factor in their pricing, which is built around maintaining their systems and the cost of the toner and paper.

I work for a printing and shipping company. Those copier systems are very temperamental and we constantly have to have them serviced, for little things. Paper costs are high, due to supply chain issues, stemming from the pandemic. 3 years on we are still way behind previous stock levels and cannot get certain papers that were plentiful, before, especially gloss papers. In the rush to fill orders, substandard papers have been substituted and the quality does make a difference, both in how it feeds into the printer and how the toner reproduces on the page. For instance, there is a big difference between Hammermill paper and Xerox brand paper, even at the same weight.

Print On Demand sounds great, from a publisher standpoint; but, the reality is often that the consumer price is too high to attract enough orders to make any money at it.

There was a big initial push for Print on Demand publishing, especially with Vanity press houses, like Create Space and iUniverse (among many others); The titles were printed and sold as non-returnable and what you ended up seeing was authors generating fraudulent orders through booksellers, knowing that they couldn't return the titles. Authors would constantly badger booksellers to carry their title, without a public demand for it or any marketing to support it. At B&N, after problems with this, the company went to requiring payment up front for ordering print on demand titles.

There have been similar questions as to why publishers don't return to cheaper newsprint to hold costs down and the simple answer is that newsprint isn't cheaper, anymore. When publishers moved away from newsprint to other papers, the demand for newsprint stocks plummeted and papermills stopped producing it; which means it is more costly per unit, now. Also, consumers expect a certain level of reproduction and you would have to retrain them to accept a step back. It's like getting rid of streaming and cable platforms to improve the quality of network programming, by concentrating focus on them, again. People aren't likely to give up the freedom that variety gave them, even if the overall quality is far worse.

I can almost guarantee they do not have the rights, in most cases.  I laugh when I see a lot of disclaimers on things, purporting their appropriation to be either public domain or fair use, just because they aren't making money off of it.  I wouldn't want to try that in court, in most cases.

Here is another aspect, which you mentioned there, that I have seen first hand with print on demand:  many of the reprints are haphazardly scanned from an old original, with no effort put into cleaning it up or correcting errors.  I have seen multiple instances where the text of a print on demand title suddenly turns to jibberish, because of an error in scanning or a flaw in the original that the software could not recognize.  This is another aspect I see at work.  Copying or scanning uses software that has to interpret what it scans and reproduce it the best that it can, based on the programming.  We get people providing us with an old hard copy original to try to reproduce something, rather than a digital source.  Already, the best we can achieve is how crisp and clear the original is.  That's just the text and imagery.  the color will be degraded because the scanner can only interpret the color.  A digital source has a color formula built into it that allows the color to reproduce at the same level, each time.

People complain about reproduction in the Archive and Masterworks editions and the omnibus editions; imagine the complaints of something done more cheaply.

These days, I only deal in digital for comic material.  Storage is one aspect; but, reproduction is as much of a factor.  You are still getting quality that is only as good as the source and the scanning technology used; but; you can frame things better or zoom or tweak, a bit, in comic reader softwares or on graphics programs.

After having to gut 20 years of accumulation, as a bookseller, and another 10, as just a reader, I don't have room nor want to deal with the "pain" of sorting what stays or goes.  I love physical books; but digital keeps me from getting too precious about them.