The big difference between distros is really how they build their distro and for what ends. Some distros are “general purpose”, some are focused on specific roles/tasks like gaming or programming or servers, some are about stability, others are about cutting edge features. And you also have different underlying design philosophies - OSS vs proprietary, or Ext4 vs BRTFS, or Immutable vs mutable, pre-packaged vs build yourself.

So yeah, distro choice really does matter. The wide range of choices don’t exist because people are being contrarian; they exist because linux can be shaped to different purposes and goals.

But I think the message to new users is also correct: distro choice doesn’t matter much if you’re starting out and just want a basic desktop environment. Whats going on in the backend or the design philosophy of the distro doesn’t change the experience for most end users doing day to day tasks. A KDE or Gnome desktop environment with Firefox will feel the same, and gaming or word processing will be largely the same. It’s when you want to go beyond generic use that the distro choice starts to matter…