Which part do you see that is not performance in that benchmark which shown the average time? I have tried benchmark on my own and PHP took longer than RubyJIT.
Command being timed: "/usr/local/bin/ruby --jit -W0 nbody.rb 50000000"
User time (seconds): 249.30
System time (seconds): 0.58
Percent of CPU this job got: 100%
Elapsed (wall clock) time (h:mm:ss or m:ss): 4:08.97
---
PHP 7.3.11 (cli) (built: Oct 24 2019 11:29:52) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.3.11, Copyright (c) 1998-2018 Zend Technologies
with Zend OPcache v7.3.11, Copyright (c) 1999-2018, by Zend Technologies
gtime -v php -n nbody.php 50000000
-0.169075164
-0.169059907
Command being timed: "php -n nbody.php 50000000"
User time (seconds): 248.02
System time (seconds): 0.49
Percent of CPU this job got: 99%
Elapsed (wall clock) time (h:mm:ss or m:ss): 4:09.82