Interesting!

I made the following changes:

#!/usr/bin/env perl

use v5.36;
no warnings 'experimental::for_list';
use Getopt::Std;
my %opts;
getopts( 'hvi:', \%opts ) or die "getopts failed\n";
my $verbose;
my $infile;
for my ( $k, $v ) ( %opts ) {
    state $dispatch = {
        h => sub { say 'HELP!'; exit },
        v => sub { ++$verbose; },
        i => sub ($file) { $infile = $file; },
    };
    my $code = $dispatch->{$k}
        or die "*** BUG: no handler for -$k.\n";
    $code->( $v );
}
say "infile = ", $infile // 'undefined';
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I couldn't see any reason to pass $k into the sub; also, made use of sub signature.