Because Polish is so much easier than English! (Okay, okay, maybe not, once you start talking about verb aspect, but nonetheless, it's worth pointing out amidst all the people complaining that "Slavic languages are so hard!" that no, in reality they've got a lot of things that make them easier, but sadly those traits often get ignored/overlooked by language learners)
I must say, these first few lessons have been made really lazily. Milk and bread are everywhere, along with maybe 2 or 3 verbs, interchangeably. Why couldn't Duolingo make it more diverse, add a marchewka or a ziemniak, karczoch, pietruszka, sok, piwo... And more activity, rather than just to be and to eat. It can be discouraging.
Is Polish the only course in which you had this feeling? Because there are a lot of technical limitations to how the sentences are created, which means that the first lessons/skills are rather repetitive, true. It's just not possible to do anything else.
A Duolingo sentence in lesson X has to use only the lexemes which were introduced before or in the lesson X itself. The maximum (and not recommended) number of lexemes (words, to simplify) in a lesson is 9. A course like Polish has also to take grammar into consideration, it would be easier to make the sentences more varied in a language like English or Spanish - we have to introduce not only vocabulary, but also the grammar very carefully, not to 'overload' the learners because that would discourage them.
I understand, Polish is a difficult language and you've got to take it easy. I don't remember having similar feelings in other courses, however in Italian (specifically in Clitics but also a couple of other lessons) I found that sentences included things that weren't introduced in the lightbulb info page. So far for me it was the hardest lesson due to this issue.
Are there plans to create grammar info for Polish?
The Polish course has Tips & Notes (the lightbulb icon) up to the "Determiners" skill, with more planned. However, those are only accessible through the browser version, unfortunately.
I believe perhaps Italian (for sure Spanish) may have the lightbulb Tips available in the apps because the courses created by the company (and not the volunteers) may all already use the new format of Tips which is supported on mobile.