How to clear html from all tags leaving the main ones?

Question

Parsing

I'm looping through various regular expressions
like <(?:"[^"]*"['"]*|'[^']*'['"]*|[^'">])+(?
and testing here - https ://www.regextester.com/93515
almost copes - but the code inside the script remains and other roughness
Share the solution - I parsed the html page - I want to leave only the "main" html code - with the main tags paragraph, title, bold - yes some more or less universal solution
?