I cast my vote 3-5 years back. I’ve been using Zen 3 ever since it launched. Began with the 5600X, moved to the 5900X, then the 5800X3D. My oldest is now on a Strix XE with his 5600X, while the youngest will have a Strix-F and likely use either the 5600X or 5900X. He might eventually upgrade to an X3D, and I’m thinking about a potential 9950X3D upgrade.
I currently have a Ryzen 5 3600. Released in 2019, I purchased it in 2021. Meanwhile, I'm considering upgrading to the older 5700X3D or even the newer 5800X3D, hoping to find a used one. (Finding new 5800X3Ds is quite rare these days.)
You set really high expectations. Any X3D CPU outperforms the 8700k, and the 9800x3d is probably the least interesting among them.
This processor delivers performance that surpasses the 6GHz 8700K. It's been outperformed for a while now.
Looking at some benchmarks, it looks like the 9800X3D is the first CPU ever that is 2x the performance of the 8700K in gaming across a range of titles. On average, if the 8700K gets 100fps in a game, the 9800X3D is the only CPU that could give you 200fps. The 5800X3D or 12900K is only about 50% faster. The 7800X3D or 13900K is only about 75% faster. And the 9800X3D is finally 100% faster. That is indeed a high bar. But it's not that uncommon. It's the bar I have for GPU upgrades - I'm only interested on RTX 3080 or better performance, because that's roughly double the performance of my RTX 2060 Super. After I upgrade, the next card I'll be interested in would have to be more powerful than the 4090 - so probably 5090 performance or better.
Sure, I'm in the same situation—I only upgrade when I notice a significant performance boost. Regarding the question, I purchased my 5600 in spring 2023, though it's essentially a 2020 CPU hiding under the surface. I haven't felt the need to upgrade either my 5600 or my 2070 Super anytime soon.
Beyond just the CPU, the MOBO offered several improvements. A key factor was avoiding being limited to DDR4 while DDR5 RAM became available. Another reason was the need for smooth gaming at 1440/4K resolutions, which only improved after recent titles like Stalker 2. I usually choose the top options based on reviews, such as the 9800x3d. Delaying the upgrade might have led to a better performance with the 9900/9950x3d instead.