Thanks for the answer !
You say no mobo change would be required anyway, but would a B450 hinder overclock significantly on the 3600 ? Unless I'm missing the point and overclocking doesn't actually matter that much for film editing and rendering.
Anyway, turns out I might be interested in those CPUs myself too. I had been asking questions about the i5-9600K cause I wanted to buy one, but I'm starting to wonder whether I might make a better choice by picking the 3600/3600X over it. I will be overclocking it most probably, and will mostly use it in gaming scenarios, although I do sometimes do a bit of editing and run C, C++ and Python based programs. In both the Intel and AMD scenarios I'd probably get a new mobo and cooler (current MSI Z370 A-PRO and Be Quiet! Pure Rock on an i3-8350K @4.5GHz). But prices on the X-570 mobos seem like a real issue to me right now, so I'd probably settle for an X-470 I guess ? I don't know whether the non-X version of the 3600 is better or worse for overclocking either, nor what cooler or X-470 mobo I should go for.
As for AMD GPUs, I'm wondering whether the RX 5700 XT could be worth an upgrade from my GTX 1070 once aftermarket cooling solutions and drivers are fully sorted out. I'm currently playing at 1080p144 with a FreeSync compatible monitor, which is why I'd be interested in AMD GPUs. I don't think I will be making the switch to 1440p anytime soon cause I care about the refresh rate and would probably need at least an RTX 2080 to make really good use of 1440p144, not to mention screen tearing in that case unless I pay extra to get a G-SYNC monitor. My only concern is whether that decision would be enough of a future investment (e.g. will I be feeling like I should switch my GPU again in less than 2 or 3 years).