A few indie devs who hated the idea of storefronts because of the bad taste of Apple self published only on their website. When they finally (after years) switched to steam, every single one of them shared how they got like a multiplier of sales.
One indie dev shared how he made more in revenue in a month on Steam than he did in a decade of self publishing.
That’s life-changing.
Apple is the same deal, though. There’s a reason there’s a lot more solo devs/small teams making money on iOS than Android. Their ecosystem doesn’t do all the work for you, but it absolutely provides a lot of help. You might not like, for example, the Human Interface guidelines, but the enforced consistency in behavior makes a lot more people a lot more willing to buy things.