We are still in the Wild West Phase of SAAS.
I do this for all sorts of applications.
Not going to happen..
If I am skilled enough, I can mod the piece of software to do whatever I want (this especially applies to games), or can swap out pieces with other pieces (e.g. replace the built-in compiler of an IDE with a different one).
A pure SaaS environment? I'm completely at the mercy of the operator now. I am locked in into whatever decision the operator makes, I depend on them keeping their service available 24/7 (because when they go down, I can't work and make money), I depend on them not getting bought out by a competitor that then decides to close up shop (either to get rid of competition, acqui-hire or the specific SaaS service is unprofitable), I'll have to pay whatever price the operator wants (which is particularly insidious given the SV model of price dumping, monopoly formation and subsequent extortion), and in most if not all cases I have no way of modification (userstyles/userscripts just don't work in compiled JS/CSS apps any more without a lot of work). And to top it off, for many SaaS solutions I have to pay money to keep using it under a contract, which is an obligation on my future budget.
> We were slaves to the mainframe! he said. Dumb terminals! That's all we had. We were powerless under the big machine's unyielding central control. Then we escaped to the personal computer, autonomous, powerful. Then networks. The PC was soon rendered to be nothing but a "thin client," just a browser with very little software residing on our personal machines, the code being on network servers, which are under the control of administrators. Now to the web, nothing but a thin, thin browser for us. All the intelligence out there, on the net, our machines having become dumb terminals again.
An extremely underappreciated approach for development and distribution is targeting the browser as a sandbox for fully local applications (embodied in static files—or better: as a single file). I see lots of people making apps and throwing them up on GitHub Pages, but rarely do the developers package them up into a form that you can download from the Releases tab from the associated repo and then double click to run. At best, they'll point at the repo with instructions in the README about running npm or yarn.
(Then again, if their build processes would also target the browser's JS engine and standard browser APIs instead of NodeJS and its proprietary ones, then the entire exercise of setting up an NPM-based development environment need not exist, either. Oddly enough, people who think of themselves as JS developers and spend their days writing web apps seem to either really dislike the thought of actually using the browser, or they're so afflicted with tunnel vision that they've missed the obviousness of using the browser runtime in this way.)