Unless you’re installing new softwares or opening unwanted documents, mails…etc there is no need to care about security updates as its just a way for these companies to push you install their new products, threats enter your computer only while you invite it by trusting websites and running executable (.exe) by installing softwares…
As long as your pc is lightweight as mine, you should have no problems 
Dont trust websites blindly and continue using websites only you’re very familiar (yt, amazon, reddit, quora, flipboard,…etc)
and turn off remote desktop connection
As long as i stopped the habit of installing lot of softwares, focus on minimalism with softwares, i have never faced bsod or computer is 1000x faster.
The websites which should be expected to stop functioning are those who heavily rely on chromium. as for instance, Spotify is the number 1 website expected by me to go down due to their constant tech/ui changes and heavy dependency on chromium… As for other websites which doesnt depend on chromium, everything should be functioning fine for the next 2 to 3 years (Samsung TV browser which is on my smart tv hasn’t received any updates for last few years but still loads most of the websites correctly, considering that fact, brave is currently technically advanced, so even without brave team taking care by sending updates and just shields continuing to do its work responsibly, there should be no problems for the next 2 years)
For me, my current plan is to shift to win 10 only if Win 8.1 becomes so unusable, correction, Win 8.1 is a Legendary OS, it will always be an Perfect OS and be known for it’s Speed, its brave browser which should be expected to become unusable, currently for my use case, it has zero bugs but without future updates, the number zero can go to hundred at a certain amount of time, but considering the perfection of its current state now, it isn’t going to be happening anytime soon. As i was saying, only if brave browser becomes unusable, i will make the move, i can understand that this isn’t brave team fault and blame is on the chromium developers for their irresponsibility to just follow the crowd/trails of Microsoft.
Right from Scratch, If Brave has never used Chromium and used a new engine called Blazekit as i said on the other post, Brave Can Confidently say, Google let you down ? Dont worry, Come to us, Our browsers are supported for Legacy windows operating systems such as Windows 7 and 8.1 and brave could’ve steadily gained ~10 million users as almost 35 million users are still running Win 7 and Win 8.1, but the problem now is brave stuck their head deep into the crypto tech and follows bandwagon, thus updates from brave team will mostly deal with wallet stuff and it will be hard to get the attention of brave team to do something about this situation…
on a sidenote, just discovered the fact, im not the only one who was thinking Device eject icon on win 10 and 11 was bad, the user who posted the previous video had made an update for the current latest version of windows and has a solution for bringing this icon as well as other win 8.1 icons.
i love these icon packs and i hope this should work good on Win 10 as well(if i update to it someday in the future), one of the main things which i found it to be bad on win 10 and 11 is the taskbar, they are not as good as win 8.1, specifically talking about the currently opened programmes, on win 8.1, everything is transparent and beautiful
but on win 10 and 11, there is a thick line with lighting under the icons which i find it bad…
Hopefully some developers in future, for their love of win 7 and 8.1, provide options to customize all these… There was a time when Microsoft was really high and obsessed with customizations, especially during Win 7 and 8.1 era, but sadly they dont care about offering customizations and variety anymore, also most of the talented developers and Engineers who worked for Windows 7 and 8.1 has Left the Microsoft company.
The rise of android and tablets has ruined the excitement for evolution of windows, sad reality.