How to interpret fractions as numbers in sheets?

You can convert text strings like 1/2 and 2/3 in column A2:A into decimal numbers like 0.5 and 0.666 like this:

=arrayformula( 
  iferror( 
    regexextract(trim(A2:A), "^(d+)") 
    / 
    regexextract(trim(A2:A), "(d+)$") 
  ) 
)

In the general case, there is not much point to try and implement a parser to evaluate a text string as a spreadsheet formula. It is much easier to use the initial = and let Google Sheets do the hard lifting.