[quote=@Dagger]
<Snipped quote by Andreyich>

That’s an interesting point, and I definitely don’t doubt it. However I also have a couple Latinx friends who do use “Spanglish” in their daily life, so I wonder if there’s some variation across people from different cultures? Living in the southwestern region of America, we have a lot of people from Mexico in my county, and it seems to vary even person to person whether they weave Spanish into their speech or not.
[/quote]
That is a matter of dialect vs not knowing the language. "Spanglish" is from my experience spoken by people with a fine grasp of the English language but have learned their own specific variants of it. 

Of Latin American countries I have only been to Cuba and Mexico (and admittedly much more the former), but when off a resort or airport I promptly found the behaviour I described wherein attempts to speak English did not include Spanish elements. When I switched to French with a few of them it occasionally happened that they threw in a Spanish word or two, but that is a product of the two languages being very similar, and while not completely accurate a good comparison would be someone from the British Isles using "rubbish" in the Americas when they should have said trash. Moreover, diasporas and people from the "old country" tend to develop very distinct cultures.

As a comparable example is here in my native Belarus the vast majority of people speak a transitional language known as Trasianka that is a mixture of Russian and Belarusian. The exact proportion of the mixture depends how far East you live, but this isn't because they don't know either of the languages poorly, its simply because this is what they gained fluency in.

So, back to my original point. People who have not gained complete fluency in English will not throw in words from our first languages. They're not idiots, they're well aware that 9/10 times this will make the person they are speaking to only more confused. Indeed, as an English speaker who tried (and admittedly failed) to master German, when I was in Germany I did not insert English words into my German speech save for the rare exceptions I came upon a person I knew for a fact had some measure of English proficiency (mostly Munich airport staff).