While this is a significant issue, there is a more practical approach to this. It's not
all doom and gloom and it's not like anyone using a pre-Nougat device will be locked of online access. Keep in mind that
this is Let's Encrypt web certificate matter, so the scope is actually limited and conditional affecting only some web
sites and when using a Chromium-based browser.
-- Let's Encrypt has a healthy and growing usage base, but its market share numbers are still dwarfed by the
long-standing, conventional CA (Certificate Authorities) suppliers. Even scumbag GoDaddy is a bigger player in this
market. Most web sites are still using certs supplied by the long-established, conventional CA's,
https://en.wikipedia.org/wiki/Certificate_authority
At 0.2%, that's in one aspect not much, but that's also 0.2% of a massive number, the issue being there are billions of
web sites out there so even a tiny percentage still involves a lot of web traffic.
-- This is a web browser security certificate matter, so it will be limited primarily to web browsing, and only when
trying to access web sites relying upon Let's Encrypt certs. Also, Let's Encrypt is taking this issue seriously so it
remains to be seen if any kind of workaround might come about.
-- Most other apps (i.e. your email app, your calendar app,Instagram app, etc.) use their own integrated authentication
scheme, not the host operating system web browser certs. The problem is tied to the fact that Chromium-based web
browsers rely upon the host operating system's web certs -- that's why using a Firefox web browser won't be affected by
this either -- it's always used its own, integrated security cert store instead.
So if you are running an older Android device, this is going to be a serious issue but not likely to be as bad as some
media sites are claiming it to be. But it is adding yet another incentive to upgrade to a new
or newer device. The Internet has devolved into a real messy place so intentionally running outdated devices and
software is a risk.