Insufficient resources often researchers having limited resources such as funding, access to participants or data, or time constraints. This can be very challenging to conduct high-quality research.
Also, academic research is a time-consuming process that requires a considerable amount of effort and dedication. Researchers need to spend a lot of time reading literature, collecting data, analyzing results, and writing up their findings.
Ethical acknowledgements, in this aspect, most research topics involve human subjects and/or delicate issues that require studious attention of ethical principles which adds complexity to the research process and require additional time and resources.
Finally, complexity of the subject matter, Where some research topics are difficult and demand an indepth understanding of the content, it can be strenuous to design research questions, collect data, and analyze results.