There is cheating on tests taken remotely. There is cheating on tests taken at test centers. Overall, there is more cheating than anyone really wants to admit.
It is true that providers of remote tests face issues that providers of on-site tests do not. But given the ongoing (and long-lasting) issues with on-site testing, we cannot say that it is the “gold standard.” We probably cannot even say that it is more secure than remote testing, as there is only anecdotal evidence to support that claim.
On-site testing is a wonderful thing. But it is far from perfect. And, by god, providers have been slow (very slow) to address some of its fundamental weaknesses. Maybe that slowness has contributed to the quick growth of remote testing in recent years.