So according to Merriam Webster bread is: a usually baked and leavened food made of a mixture whose basic constituent is flour or meal
And cake is: A: a breadlike food made from a dough or batter that is usually fried or baked in small flat shapes and is often unleavened B: a sweet baked food made from a dough or thick batter usually containing flour and sugar and often shortening, eggs, and a raising agent (such as baking powder)
And yet some people don’t think that cake is bread.
What’s your opinion?
You asked the question, “is a cake a sort of bread” and the dictionary is explicitly stating “cake is a breadlike food”.
Are you instead asking if “lots of people” is a more reliable source than the dictionary?
No but like something being bread like doesn’t mean that it is bread, just similar to bread.
Something can be breadlike without being bread, in a similar way to how whales are fishlike without being fish.
The dictionary doesn’t dictate how words should be used; it reports how people use them. Consulting a dictionary is a way to find out how “lots of people” use a word.