[the8472]

The upgrade problem is something that google created with android devices being stuck on old kernels, now they're trying to paper over that mess by moving things to userspace. That may solve this particular problem but it creates a new maintenance nightmare with hundreds of different applications bringing their own congestion control and different transport implementation on top of dozens of differnet TLS libraries. It seems like a little more patience and ensuring that devices remain upgradable could give us most of the advancements without the downsides.

[afiori]

That is a possible source of error, still there is the issue of network devices that implement ossified versions of internet standards. For example when they tried to use different kinds of compression in unencrypted HTTP it came out that a lot of middleboxes would simply "fix" the content-encoding header to be either gzip or deflate, regardless of that making it illegible.