I don't necessarily disagree with any of the few specific comparisons the author makes. Maybe Tim Curry's Steppenwolf does look better. But this small set of specific comparisons, even if they're uncontroversial, don't provide evidence that a CGI effect on average will look worse than a practical effect. I can think of plenty of examples of practical effects that looks terrible and CGI effects that look great (and, crucially, aren't even noticeably CGI to most viewers).