Adobe Flash disabled in latest Safari Technology Preview

Its not as if anyone who is listening hasn't known this was coming. Steve Jobs drove the first and ultimately fatal nail in Flashplayer's coffin ten years ago with his open letter detailing why Flash would not be permitted on iOS. It took several years for Adobe to bow to the inevitable but they drove the final nail In July 2017 when they announced all product support would cease by the end of 2020 giving the last holdouts three years to convert to HTML5.

I don't remember the last time I had a problem accessing a website on my iOS devices because I didn't have Flashplayer, but I ran into a site this week on MacOS that required Flashplayer for access. It turned out the site had been dormant for four years.

Be that as it may ...
I'm still regularly updating FlashPlayer when Firefox recommends such — most recently as yesterday.
And I'll never be able to get rid of it given my large folder of .swf files.

I've got Flash installed and updated on my MacBook Air running Mojave. Don't notice it.

I do not have Flash installed on my iMac running Mojave. I have not noticed the lack of it.

Don't know what I'm (not) missing...

But they may become unplayable when there is no longer a browser that supports the Flashplayer plugin

There are apps and online services available to convert .swf files to MP4. You may want to consider that option if those files are really important to you.

The easiest option is just to keep the last version of whatever browser that can run the plugin and use it strictly offline to run those files.
I may be retired (if not retarded) but I have no intention of wasting time or other resources to convert .swf files to something else.

Ditto. On my previous machine I had a piece of software that allowed Flash always to remain disabled and only opened when I needed/chose to view something with it. That software and Flash were removed at the point I realized neither was ever being used.

It turns out there is at least one browser that requires Flash for some functions.

I registered for a webinar and, in the instructions they advised: "We recommend using Google Chrome, Microsoft Edge, Firefox or Safari as your browser as these are the best for live streaming reception. If you use Internet Explorer 11, you must also have flash installed and working."

That is likely because Internet Explorer 11.0 does not fully support HTML 5 so Flash is a fallback on that particular site for people still using Internet Exploder. Microsoft has dropped Internet Explorer and their current browser is Edge which is fully compliant with the HTML 5 standard and drops support for ActiveX and other Microsoft proprietary technologies.