Yeah I agree, but finding those errors at the end of the cycle is extremely painful and time consuming.

Really depends on the size and the budget of the project. If both are large enough you should really outsource this task and superannotate has both a great platform(free for academics,I used this) and according to g2 they are the highest rated. A friend of mine told me that if you want automotive data then scale is more specialized there

yup, there are a lot of inconsistencies there. Engineers never learn about the importance of annotation/data quality, in best case they skim over the topic. In reality successful companies spend most of their budget on data annotation.