Should you sell on Instagram or your own store?

Both, with different jobs. Instagram to be discovered and to make buying easy for a first-time buyer; your own store to keep the customer and the margin.

In more detail

The commission is not the main cost of selling only on social. The main cost is that you never learn who bought, so you cannot reach them again except by paying the platform to.

What to do about it

The follower count almost never matches the sales. Engagement in the comments is a far better signal than reach.

Short-form video is the cheapest reach available right now, which is exactly why it will not stay cheap.

Influencer spend works when the audience already buys that category, and burns money when it is chosen on follower count.

The mobile app angle

The point of an app in this picture is ownership: social brings somebody once, and the app is where they come back to.