Hi, thanks for replying.
I don't at all "curse" clone generators. Game clones are like clichès, they are popular for reasons, I understand that. For people who simply want to reinvent their favorite FPS, there are numerous ways they can do that, and I'm happy for them. But a clone generator won't suit my needs. I need a general-purpose engine that will not constrain my options in unnecessary ways, because my inspiration usually involves things that I've never seen done in any other game, and I'll have to design and program it myself.
Coding is not an issue for me. Each time I've decided on an engine to stick with, the first thing I do is learn that engine's scripting language if I don't know it already. I'm certainly not an expert programmer, but I have no problem scripting what I need, if I can actually find an engine to work in.
Graphics and audio is not an issue for me. I am a 3D artist, and I make my own sound effects and music.
The holdup is not all the things surrounding an engine, it's simply finding an engine (suitable to the general-purpose need I described) that I can get working. Unity is spoiling because it is ready to get and go right away. There are numerous unity-like engines (ie the list in the original post), but the get-and-go setup is not so common. From installers that don't work, to total lack of documentation, most engines have problems that make them useless, and the only way to know is to take the dive and give one a shot. I spent months learning Godot before I gave up. The same/similar is true for several other engines.
Unity has been turned into another clone generator. It's perhaps the most versatile clone generator around, but it makes things I want to do impossible. Beside that, they, as a company, have totally lost my confidence. I won't even play new games made with Unity, those crooks cannot be trusted at all and their crap can stay the hell away from my computer. I took some time to check out Unreal a couple days ago (another respondent suggested it), that's one I'll consider a last-option. For one, it uses visual scripting, and that's the brakes. I will prefer Castle or Titan, where I can write out a script in the conventional way, before Unreal. Also they make their engine only available through Epic. I didn't think of listing this as a qualifier, but having to go through a service like Epic for an engine is also the brakes. That's the only reason I don't consider Leadwerks, they are only available through Steam. If you have to rely on one of those services for your engine, and something goes wrong with that service, then all your work is in jeopardy. A proper engine has the reliability of being standalone.
I appreciate your advice that "If you want complete freedom, you have to develop your own engine", but I don't believe that's true. There are SO MANY engines. Surely, SURELY there has to be one out there that is actually useful in a non-clone context. Over the last few days, I have come to feel like I am getting closer to one. I have found information that I believe may lead to a solution to Stride's big problem, which would be a big relief, but I'm having to wait on other people for help with that, so that progresses at their convenience. The Titan engine installer has passed AV inspection, so that one is now a possibility that I need to take a closer look at if Stride turns out to be no good. In the unfortunate situation that Stride and Titan prove to be non-options, then, my plan presently is to fall back on Castle. Castle is the one fully-working engine I have found that is get-and-go ready and has everything I need. But ooooh I really want to avoid it if possible, because that one's design direction makes it a big gamble, and I don't have anything to wager that I can afford to lose. That's the whole point of this thread, for if anybody knows of an engine I haven't tried yet that will be a better option than Castle.