I've been using LosslessCut for a few years now. It's really easy and smooth. It does exactly what I want and what the name says, and I couldn't ask for more.
It is a good tool, but for me it only trims from the keyframes. To trim precisely, it has to re-encode, which, unfortunately, does not work on my machine for some reason. So, I just stick to ffmpeg cli.
I suppose that makes sense given that information is encoded as a series of key frames interspersed by 'I-frames" that simply encode the delta to the previous key-frame when using most compressed video algorithms. So cutting in-between key-frames doesn't really make sense since the I-frame would no longer have anything to reference it's delta to.
This has always bothered me, I suspect it's the same underlying reason most video players can't do reverse frame-by-frame. But Quicktime allowed it twenty years ago, so it's possible. I suppose you'd have to actually decode the entire keyframe interval and use the resulting frames as new "baked-in" keyframes so to say. I suppose that's more or less what djv and other frame checkers do under the hood. But I don't know what I'm talking about so...
It's a slightly different use case, I default to Losslesscut and switch to Shotcut when I need a vfilter or if I'm just generally willing to concede to making a lossy cut.
Shotcut is way more flexible but I can make a quick clip in Losslesscut with probably 1/3 the number of user effort/inputs. Let alone trying to remember every ffmpeg parameter under the sun just to get consistent usable output