Why is Software Update, Not Notifying me of Apple Software Updates?

I did the safe mode restart, and it did let me download the one app, that it couldn't, along with another. However, it didn't inform me about the security update! I only got that notification in System Preferences, along with the never -ending Catalina update notification, which I sure wish I could figure out how to stop it from showing. That there's now two different apps to get software update notifications, only confuses the issue, what was Apple thinking? Isn't one enough? I really find it frustrating, discovering yet another app that was working just fine, but now it updated, which usually means having to take more steps to do what used to require only one!

Plus, the App Store still doesn't inform me of various other apps needing updating, I have to go to Macupdate.com and scroll through all their daily updates, to find them. And then it redirects me to the App Store! Why the App Store didn't let me know, I don't know.... It's pretty frustrating to have used Macs since the early '90s, only to find myself experiencing a greater learning curve, or should I say re-learning curve, to do the things I've always done, with far less thought.... You know, when Macs were the brand that was "more intuitive"... back then.

No, they are updates that are available for Mojave, and even versions before that. The issue has nothing to do with what OS I'm using, as it's always worked even when I was using old OS, and it works sometimes now, just not always. And with one app, it kept telling me there's an update, yet everytime I opened the App Store, it just kept spinning around, unable to be downloaded. It finally worked after about two weeks of that.

Maybe something is screwing up on a deeper level, as the OS is ignoring some of my preferences, too, like my mouse is shifting things right & left, despite my not having that selected, and Spotlight keeps showing email message in its results, despite having that deselected. It's really frustrating having a new computer, and new OS, and so many things are going haywire...

I just bought it, but it was a 2017 model, & came with High Sierra, I then updated to Mojave. I don't like updating when new OS come out, for since Snow Leopard, it's seemed like every new one has lots of bugs that need to be worked through, until it becomes a very stable system. In fact, I wish they didn't feel they have to release a new OS every year, as it only ends up causing wasted time & hassles, as things that worked fine for years, are now different, or apps are changed so much they become unrecognizable, losing their simple usefulness, & in ridding themselves of superdrives, means we now have to add an extra, external piece of equipment, so who cares if the screen is an 1/8" thinner, it's just dumb.

But I don't understand why the focus on what OS I'm using, I'm only talking about th software update feature, and a couple preference selections, not working correctly . And I don't see how it matters that I'm using Mojave, everything should still work as it should, no?

Obviously, I'd rather use Software Update, but if it's not showing me apps, I find out which ones are updated by going to MacUpdate. Maybe I'll avoid the potential of adware, by finding out which apps, then open the app on my computer, so it will update itself, instead of downloading from Macupdate. However, that doesn't help my Software Update app work any better...