Agency influence over tech stack

I’m researching in this space and I am intrigued about what percentage of stores go out and find their own apps for their tech stack versus those brands that use agencies to influence these decisions. Also wondering where else people get advice on which apps are worth it?

I’m on the other side of this (I build apps), so take it with a grain of salt, but from my conversations with merchants the split is mostly about store size. Small shops almost always pick apps themselves — App Store search, review counts, and lately just asking ChatGPT or watching whatever YouTube tutorial comes up. Agencies enter the picture when someone else is building the store for you, and then the agency’s usual shortlist tends to win, because the merchant never really sees the alternatives.

As for where else people get advice: Reddit, forums like this one, and honestly just other store owners they know. Would be curious what share your research ends up putting on agencies — my sample is obviously biased.