Many people using a VPN have the same IP address, and cloudflare and others can track that behavior and block those IP addresses. Different sites do it for different reasons, some do it for a little extra security because attacks often come routed through a VPN, some do it to block country specific content like Netflix does.

My grandma does the same for Costco('s) lol

That’s not a smoking gun, that’s a shitty chain email joke. It’s slightly suspicious but I need more evidence than that.

Basically means that the core OS files and systems can’t be changed. Everything else is stacked on top, and usually it means that you can rollback to a previous OS version if an update breaks something, without relying on any other image backup software.

Usually results a more stable reliable system, or at least one that’s easy to revert to working.

The downside being a reduction in flexibility and customizable options, and most programs need to be “containerized.”