I think the truth is somewhere in between. I find label studio to be lacking a lot of niceties and generally built for very the average text labeling or image labeling use case, but anything else (like a multi-step agent workflow or some sort of multi-modal task specific problem) it is not quite right for and you do end up doing a bit of trying to build your own custom interface.
So, imho you should try label studio but timebox and really decide for yourself quickly if it's going to work for you in a day, and if not go vibecode a different view and try it out or build labeling into a copy of a front end you're already using for your task if that's quick.
What I think we really need here is a "lovable meets labelstudio" that starts with simple defaults and lets anyone use natural language, sketches, screenshots, to create custom interfaces and modify them quickly.
I'm ostensibly an expert in the product and I probably use that 90%+ of the time (unless I'm testing something specific) -- using a sketch as input is a cool idea though!
Disclaimer: I'm the VP Product at HumanSignal the company behind Label Studio.
So, imho you should try label studio but timebox and really decide for yourself quickly if it's going to work for you in a day, and if not go vibecode a different view and try it out or build labeling into a copy of a front end you're already using for your task if that's quick.
What I think we really need here is a "lovable meets labelstudio" that starts with simple defaults and lets anyone use natural language, sketches, screenshots, to create custom interfaces and modify them quickly.