Check Dates in Google Forms with Regular Expressions

I found an article by Amit at

The article suggests that it is possible to add regular expressions to
validate Google Forms entries, but I cannot find any options for this,. Are
regular expressions a deprecated feature?

What I need to do is check that the “Start Date” and “End Date” on a
holiday request form are in the correct chronological sequence. It seems
strange that FORMS was designed without any validation whatsoever.