Should marketing be outsourced or kept in-house for early-stage startups?

Whether early-stage startups should outsource marketing or keep it in-house depends on several factors, including budget constraints, the complexity of the industry, availability of in-house expertise, and the ability to manage and integrate the outsourced function, but as a general guideline, if they lack the expertise or can't afford to hire full-time marketers, outsourcing can provide valuable external perspectives and skills, although it is important to establish clear communication and goals with the external agency.

It depends on how quality outsource company do you have and do you have a team member for marketing. Sometimes outsource agencies just create a content plan and some topics, put into your website an online chat and that is all. It really depends. In my experience I try to keep in house

My personal opinion is pretty much always outsource. I am reminded of Plato's Republic, when building a perfect state he poses a necessity that all should do what they are best at. A builder should build houses, a blacksmith should make tools and a philosopher should seek the truth. Same thing here, better to spend money on an outside agency and let them do what they are best at while you do what you are best at. There are so much little and big things in the early stage of a startup that you don't need the extra headache of marketing. Also, it always pays off. You will get better results with a far smaller margin of error than doing it yourself.