There's a bit of truth to what you say, but also truth in the fact ultimately the consumer pays for everything. You're right that in effect the business might absorb the loss to profit, but ultimately ~100% of the revenue is from receipts from customers in the business model you proposes of things like selling a simple business of merely producing and selling M&Ms.

Thus both of you are really right. The tariff is paid 100% by consumer receipts if you track the flow of money, but this might also still be reflected in reduced profits. The actual flow of money might be $X revenue from customers, out of the $X paid from customers $Y is taken out for tariffs. $Y comes from the dollars received from customers but still reflects lowered potential profit if $X rose by less than $Y after tariffs started.