It's not a disadvantage, it's the whole point of IPv6: each device can, once again, have it's own IP address like it was meant to be. That you probably want to run a firewall is nothing new. IPv4 and NAT have corrupted people's understanding of what the internet is.
Actually I think you'll find most people just connect their devices to the internet and expect them to just work. Their mental model of the internet is probably closer to a pure IPv6 internet than nerds and engineers who have had to learn all this extra complexity required to get IPv4 to keep working.
Fascinating. Me mentioning NAT as a positive (blocks all incoming ports) prompts people to reply with a word salad that contains "crappy" and "corrupted". Fact is, NAT is being used in almost every apartment LAN setup since, what, 30 years? Its no surprise that people grew used to the implicit port block. And therefore its no surprise that when switching to IPv6, some people will discover the hard way that they now need to do extra work.
But hey, why think about it rationally, if you can throw crappy and corrupted around?
It's because people saying stuff like "NAT good, IPv6 bad" makes many people afraid of v6. It's part of the problem. Any decent gear will come with a firewall with sane defaults and most people won't know about it, just like with NAT today. If you asked someone to configure a router from scratch (ie. one that came with insane defaults) then NAT would be more difficult to set up.
Oh, the touchy-feely CS industry. I miss the old days when feelings didn't really count. I dont care if not-quite-a-whole-sentence of mine makes people afraid of things they dont know enough about.
NAT is a crappy replacement for what can be done with a simple stateful firewall though… It kind of works for one use case (where you want to block everything or have no more than one host on a single forwarded port) but hinders or breaks literally every other use case! And then if you’re behind CGNAT you’re even more restricted!
