Here you can listen to how they lisp at the same time:
What does not prevent teaching English , though after these videos, some phrases sound in my head with all these defects.
There are. Here is a famous English performer https://www.youtube.com/watch?v=vPr_iuT6YiQ
The way she pronounces L is typical for many in England, but it seems to me that she also has a defect.
If by burr we mean fuzzy "p", then, generally speaking, it is the norm of the English language, which came from French (from where it came to us for some time during the time of Catherine the Great).