If you go back in history, you will read "horrible things" about every new OS version ever released. There will always be some people who have issues and will share their experience with the world.
New OSes come with new features, address security issues, fix old bugs, and yes... because there is change, there will be some new bugs.
Overall, give me the new stuff! There's an army of coders who have a passionate interest in improving the products they work on - better performance and code-execution efficiency, better security, enhanced usability, greater "intelligence," etc. Yeah, there are also the headline features the marketing folks push that may or may not be necessary to your life... However, I would not turn back the clock, or hold back the tides of change.
I've felt this way since the days of MS-DOS. I used to say, "Every DOS upgrade has at least one new feature that makes it worth the price of the upgrade." And now that Apple's OS upgrades cost $0.00? It's a no-brainer for me.
The cautious will always wait. "Why be a guinea pig for iOS 13.0? Let someone else find the bugs!" Perfectly fine by me. The question then becomes, just how long will you wait? If iOS 13.3 isn't "mature" enough, wait until iOS 13.4. Will there be an iOS 13.5? Maybe, maybe not. But if you want that mature, fully-debugged version, just be sure to upgrade before iOS 14.0 arrives in September 2020, or you'll be waiting another 6-9 months for a fully-ripened version of iOS 14.
If you were totally averse to change, you'd still be using a flip phone, or maybe have no phone at all (snail mail still works just fine). Change is inevitable. The only question in my mind is whether people embrace change, or resist it.