Agency vs self planning May 2020

I was curious if anybody had used any travel agencies and if so what company/website did you use? I am in between planning everything personally versus going through an agency. The two locations I am thinking about are Mexico and Hawaii, I would prefer all inclusive, and including airfare. My budget is around 3500 and I would like to konw which one would give me more for my money. If you have any experience with agencies please let me know!