I don't totally agree with this. Yes, .com is the gold standard, however other TLDs are just fine, depending on the use case.
For Instagram, I would always try to go with .com, .net or .org. In fact, I think it could be argued that .org domains have slightly higher inherent trust. The new TLDs are more likely to get banned in my experience.
On other platforms, I've had no problem with them. I have several .club domains that work perfectly well on Twitter & they only cost me $.88 each.
Whatever you do, I would always recommend that you go to https://www.expireddomains.net/ & look for an expired domain relevant to your niche. One very handy secret that I'll share. Check the domain out on the internet archive - they may well have had an active social media account that you could recover & use as your own after buying the domain. I have several Twitter accounts that date back to 2008 that I picked up this way. FB is harder to recover, but it can be done.