TL;DR: Read the next-to-last paragraph
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That's a question only you can answer. The answer for me was 'yes', but it involved a few not-inexpensive upgrades to what started out as a pretty decent machine with an 8-core Intel i7-6700 CPU @3.4GHz. The bullets are in the order of how much performance improvement each had for Resolve:
- Installed a 1TB Samsung EVO SSD as my boot device; this is also where programs--including Davinci Resolve--are installed.
- Upgraded RAM from 16GB to 24GB
- Upgraded graphics card from an NVIDIA Quadro K620 w/ 2GB RAM to a NVIDIA GForce GTX 1660 w/ 6GB RAM.
- The GTX 1660 board required a new power supply; the stock power supply had insufficient capacity. Also, it had an unusual (Dell-ish) motherboard connector that demanded a special adapter to mate the new power supply to the motherboard. Amazon to the rescue!
- Installed a slow 4TB internal drive and a fast 4TB external drive for long-term storage; these 4K videos suck unbelievable amounts of disk space!
At this point, the machine is pretty good. I'm happy with the performance; scrubbing through video is smooth while editing, and I rarely encounter lags of any kind. Another 8GB of RAM on the motherboard would be good, and another 4GB of graphics RAM would be better, but really only to boost speed when rendering the final MP4. The editing experience is a dream.
So to satisfy my perfectionism, Davinci Resolve is worth the hardware investment. And once you're that far, the full-blown software is a niggling extra, so yeah, I'd say go full Monty on it. You can start easy with DR, accepting all the defaults and so on. If and as you want to do more, you can. And whether or not you ever create a video project worthy of Cannes or Sundance, you will simply never outgrow Resolve.
But that's just me. You have your own budget and other criteria, and there are many good answers to video editing hardware/software systems. I'm sure you'll wind up with a system that makes you happy, because you're doing your homework first.