We have been seeing these reports for about a month now. Some of the regular contributors notified those in charge of the forums, but we still see these reports and have not had any status updates from Apple.
Either Apple doesn't care to fix the problem, or Apple has secretly & quietly taken those servers offline for the older macOS online installers....seems to affect macOS 10.7 to 10.13, and I think maybe even 10.14 & 10.15. I'm thinking this may be intentional by Apple due to the excruciating silence.
You can provide Apple with product feedback here (Apple won't respond):
Product Feedback - Apple
You can also contact Apple corporate to let them know your displeasure about this sudden & unexpected removal of a critical feature (Apple may respond):
Contact - How to Contact Us - Apple
You may also want to check out your local consumer protection laws to see if any apply since Apple did make Internet Recovery Mode the main option for reinstalling the OS on many of their Macs. Many people don't have access to a working compatible Mac in order to download & create bootable macOS USB installers.
In the mean time, your only option is to create & use a bootable macOS USB installer, but this requires access to another Mac compatible with the OS installer you want to create. If you have access to a compatible Mac, then you can use the instructions in this Apple article for creating a bootable macOS USB installer:
Create a bootable installer for macOS - Apple Support
For a 2010 laptop you generally need a Mac from Late-2009 to 2018 to create a bootable macOS 10.13 USB installer, or a Mac from 2008 to 2015 to create a macOS 10.11 USB installer. You can use the information in this article to identify which Macs are compatible with various versions of macOS:
https://eshop.macsales.com/guides/Mac_OS_X_Compatibility
Another possibility to download & create a bootable macOS USB installer if you have access to another Mac, but it is not compatible with any OS for your 2012 Mac would be to try using MDS. I've never personally used it, but saw another respected forum contributor suggest it recently.