>> An L2 device should not be fragmenting L3 packets. Layer 2 fragmentation used (20+ years ago) to be a common thing with bridged topologies like token-ring to Ethernet source-routing. Obviously, no so much anymore (at least I hope not), but it can and does happen.
I think part of the problem is that ISPs, CDN, hosting companies, etc. have assumed IPv6 is just IPv4 with longer addresses and haven't spent the time learning the differences like what was pointed out that ICMPv6 is a required protocol for IPv6 to work correctly. MTU issues are an annoyance with IPv4 but are a brokenness with IPv6. Knowledge with come, but it may take a bit of beating over the head for a while.
