Is it sacrilegious to ask whether or not you feel tied to macOS? It sounds like the best option might be to build/order a PC and switch over to Windows. You could use that for a while, see how much you miss macOS, and wait out the Apple Silicon transition.
I had a tier-3 base model of the 2020s, but recently returned that, thinking that it felt a little unbalanced if I wanted to keep it for the next 6 years. I've been debating between reordering it, ordering it upgraded with the 5700 and 1TB, or just ordering the tier-1 base model. As a researcher, the tier-1 is more than enough for my daily needs now and for the next few years. I play the odd strategy game, for which the 5300 will be ample, and I'm not above hooking up an external drive for more storage. In a pinch, I could even install Windows on an 80GB partition and install Windows applications on an external drive. This would be the minimal financial outlay to get me a solid work-from-home macOS setup. And I won't have to fret too much about its potentially depreciating value as AS rolls out. It could also get me through the next 4 years, or I could sell it after a few and pick up an AS Mac, since I'm not sure that I could resist a 32-inch AS iMac (hence not spending more than necessary on an iMac right now). I'm not convinced that better iMac hardware now will translate into meaningfully higher resale values later on, especially if I'm not in a position to take advantage of that upgraded hardware right now.
The other issue to consider is how much you'll be gaming and what you expect of your gaming experience. If you're only gaming 5% of the time that you're on your computer and you don't mind turning down the graphics, then the 5300 will run all of the games that you mention and certainly many yet-to-be-released titles. Spending 30% more on upgrades for a modest improvement 5% of the time that you're at your computer might not be worth it. Then again, you might think that it is. If so, I can't argue with pldelisle's suggestions.
It's a good question. I had considered getting a Windows machine but my experience of them (either personal or with work) has always been negative. I like Mac OS, I like how everything just works with my other devices. For better or for worse I'm fully immersed in the Apple ecosystem. The other consideration is having one less device and monitor to manage. Working and 'playing' on one device, and utilising the iMac screen too I thing swings it for me.