Earlier quoted context omitted.
If you attempt to use a credit card that you haven't used in years, the bank will similarly ask you to verify your identity. I don't think it's weird that unused valuable accounts need re-identification when you start to use them again. I don't mind anti-spam measures in cases which are common spam techniques. Hijacking unused accounts is common enough to warrant an approach like this.
But instagram is not a bank. I understand not wanting yet another company to have my photo (which nowadays is pretty much knowing who you are) + phone number. Plus it shouldn't require personal identification to post a photo online, especially given how easy it has became to filter out illegal content automatically.
It’s also reasonable not to want to provide Instagram not to have too much information because after all it is Meta, however it’s debatable whether sharing a photo with a photo sharing service is too much information.