Ok, have you ever thought that pollsters conduct polls only in certain areas?
Sure, in swing states like Pennsylvania, Michigan, Wisconsin, states where Trump won in 2016 but is trailing badly now.
And in states that used to be blue, where Trump won easily in 2016 but trails or is within the margin of error such as Texas, Iowa, and Georgia.
And in pretty much all 50 states.
I guess since Puerto Rico and Guam aren't being polled, you could safely call it "only certain areas".
polling companies ask certain people certain questions?
Hmm, yes, like "Are you likely to vote in 2020" and "who will you vote for". You're right, those are awfully vague and open to interpretation.
you know that your two points aren't actually mutually exclusive, right?
Actually, I do. I just find it funny that on Monday certain people will breathlessly proclaim "oh you can't trust polls, I talked to 20 people at the bar last Saturday and they all said they give false answers to pollsters"...
..and then on Wednesday the same people say "I saw 20 Trump signs in my neighborhood and only 2 Biden signs, therefore my state will be a landslide for Trump."