Venues have rules, so they're allowed to ban people. You don't have a right to do business in an establishment, regardless of your conduct. That's a traditionally conservative principle.

A lot of the content you're including in "banned behavior" doesn't come from mainstream conservatives simply expressing their political views, but from egregious behavior defended as being conservative in order to strengthen the narrative of liberal media persecution. Roseanne Barr, for instance (literally because it's early and she's first example I can come up with off the top of my head) wasn't banned merely for being conservative but for going on a racist tirade on Twitter.

Gab and 8Chan weren't deplatformed for expressing conservative views, but because their cultures encouraged and exploited racial violence for entertainment. You can disagree with the validity of that versus those sites' free speech rights, or their responsibilities for the second-order effect of their "memes," but the fact remains they weren't a victim of anti-conservative persecution. T_D's treatment isn't due to their conservative views, but their violations of Reddit's TOS.

Even the case of Carpe Donktum in the article appears to have been banned due to violent threats, not merely conservative views.

Yet conservatives refuse to even concede that the courtship by the Republican party and NRA of the extremist right and the shifting of the Overton Window of conservative activism in the direction of neo-reactionary hatred post Trumpism is even a problem, much less a relevant factor in this specific debate. The only thing conservatives seem willing to do is state that exactly the same phenomenon exists on the left, then proceed to ignore the issue completely, as if somehow they were proving "the left" hypocritical, and thus invalid. But even if the left were hypocritical, being hypocritical doesn't make them wrong... conservatism has a problem with its lunatic fringe regardless, and in most cases, an unwillingness to clean their own house is why they're getting banned, deplatformed, etc.

As far as trying to get people fired goes, employment in the US has almost always been at the sole discretion of the employer. That is due to conservative efforts and conservative belief in the free market, and they have fought tooth and nail against unions, labor rights, minimum wage increases, maternity leave, protected classes, environmental regulations, anything that would prove an encumbrance to employers' ability to fire at will or do business as they choose. I'm sorry but I have to play the world's tiniest violin for them in this case.

The premise that "conservatives will cease to exist online" is FUD and hyperbole. It's a conspiracy theory. It's not true. I have plenty of social media accounts, and I see plenty of conservative speech online. The typical conservative answer to this problem, if it exists, should be the free market - if it is the case that most or all conservative speech is under threat, then that presents a clear market opportunity for platforms to serve conservative speech.

And in fact, that's been done. And those platforms tend to fail because they're unnecessary, and because they get brigaded by Nazis and trolls. The marketplace of ideas has decided that it doesn't want to tolerate the sort of views that conservatives refuse to disassociate themselves from.