This already happened. Banks here in Brazil like to require an invasive piece of software (a browser "plugin", though it installs system services) to access their online banking websites. For a long time, this invasive software was Windows-only, so those of us using Linux had to either beg the banks to enable a flag to bypass that "security software" for our accounts, or do without online banking. The same for the government-developed tax software, which was initially DOS-only and then became Windows-only.
But nowadays, there is a Linux variant of that invasive banking "security" software, and that tax software became Java-only (with Windows, Linux, and MacOS installers, plus a generic archive for other operating systems). So things can change.
You call it blackpilling, I call it facing reality.
Even if you could get some traction, you're gonna have a bad time getting banks to support this OS, at which point it will be useless for most users, preventing you from ever becoming profitable.