Yes, Zscaler or any other Zscaler clone (e.g., Netskope, Cato, etc) -- they're all just sitting ducks, and once they are compromised, what happens to all the customers? It doesn't make any sense and shows how much we're willing to give up for convenience.
Back in Docker's day it was (basically) the only thing out there that let you reliably package up an application in a portable way from any Linux distribution to any Linux distribution - before Docker it was prohibitively difficult to build your application on your Ubuntu desktop and run it on your CentOS servers because you had to wrangle system packaging, library differences, and see the app run in the same way as it would in production. Docker turned the runtime into one consistent thing everywhere (and the ability to ship it to the deployment target).
That's less novel in 2023 but solved serious problems a decade ago. In 2023 reproducible builds are important as reflected by efforts like Debian's reproducible builds or SALSA and nix zooms way beyond that to solve downstream problems, too
I get very similar vibes to early Docker as I do about Nix today: it requires doing things very differently, is difficult ramp up on because of that, but those who pay the cost to invest the time are gaining an advantage now by their ability to do dazzling things by adopting early.
Tailscale has captured mindshare, reminds me some of Cloudflare. There are many solutions out there offering unique value props relative to what Tailscale is doing, and it all comes down to customer needs. I'm not sure how broadly Tailscale has been adopted outside of the dev / HN crowd, so that's always something to dig into.