The direct to consumer model already exists. Amazon Kindle provides this very well on a per book level via Kindle [a la carte] (and also for large groups of books via Kindle Unlimited.) There are also numerous site-licensed services which give total access to books for a time period for pay -- I used it in grad school. I also subscribe to OReilly Safari and love it.
The OverDrive/Libby model exists because it is free to the end user -- the public library is verifying you are a local resident and then using local tax dollars to fund the free service to residents.
Which doesn't imply that more aren't needed or possible.
Why couldn't overdrive simply cut a deal where a group of people (a school, a county, a company with benefits) is allowed to 'check out' a copy. Archive.org has that sort of concept for individuals of course (for free). I don't see any value added by getting the library involved (which are mostly just free internet, warming/cooling centers and bathrooms for the homeless, a source of self-help books and romance novels for a tiny section of an ageing population).
To be fair, the feature creep in public libraries is important to keep the iron rice bowl full. It would be more honest to put together a local 'activity center' that happens to have a few books.
That is literally what they did. In the US, most public libraries are at the county level (though some at the township level or city level (e.g NYPL).) The library is serving to validate residency in the county and to segment county funding from tax dollars to the private service. The rest of the service is between the end reader and Overdrive. Even the catalog appears to be a whitelabel service atop Overdrive's APIs. The Library checked-out list likely reflects an API call on Overdrive -- there is no way a county library has the sophistication to build this out.
Similarly, my employer used to pay for the OReilly Safari service which is very similar, except from corporate coffers.
Similarly, my University used to pay for a textbook service, this time from University coffers.
You can adapt it to run partially only for the things you want, if that is the case. Hope it helps
One thing that's going to have to change is the cost of ebooks. Amazon pricing is insane and I can't say that artificially scarce check-outs is a more logical solution.
My main bet is that the IP enforcement apparatus gets stronger and stronger. Now is the time to grab everything you can from whatever source. youtube-dl, libgen, sci-hub, the-eye, even the currently legal things like gutenberg and archive.org...I'm working to go essentially offline on media sources.