Businesses really need to have a growth mindset, rather than trying to save money on not using an agency much of the time you are missing out on potential returns. You are paying for experiences, best practices, multiple heads, strategy, consultation and direct support with what ever platform your using.
SMB always thinks they are doing the right thing in terms of their strategy as they read it on some blog, some guru has given them crappy advice or just won’t change their old tactics and find it hard to hand it over to an agency they can trust. Most of the time if the agency runs an audit they will find so many gaps and other areas to improve your ROI.
Let a decent agency get your foundations sorted for several years while they grow your returns so you can then shift inhouse by hiring people with more experience to you and can build on those platforms.