Having a lot of RAM is a game-changer for video-editing.
I've also used Flowblade, and there was a time when it seemed to outperform Kdenlive when actually editing on the timeline. I haven't used newest versions of it so that could have improved a lot I don't know. But during the pandemic Kdenlive had a great-leap forward with people seeming to dedicate a lot of time to it.
I'm using an old Intel Xeon 6-core/12 threads & a Nvidia Quadro GPU(2GB VRAM) and I have 32GB of DDR3. Old hardware that was decent when it was new.
Years ago I did probably 6 or 7 of my videos with Flowblade, but I would honestly feel held back by it if I had to use it now.
Granted video editing styles are very different for everyone.