You need to use utf8; to tell perl that the euro symbol in your script is utf8 (not bytes).

(modified to read bytes from command line, else decode fails)

use strict;
use warnings;
use utf8;

use Encode;

my $utf8 = Encode::decode('utf-8', shift);
$utf8 =~ tr![]€!<>E!

print $utf8;
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