> I think what perl6 does is also breaks 1.

No, you can use the backward-compatible syntax if you don't want to spend any time porting to the newer improved syntax.

https://docs.perl6.org/language/regexes#Perl_5_compatibility...

http://design.perl6.org/Differences.html#New_regex_syntax

https://docs.perl6.org/language/5to6-nutshell#Add_:P5_or_:Pe...