The problem isn't that they have to build their own, to me it's clear they want to. The problem is that they feel they're being shut down or invaded or whatever, when they attempt to build their own services and communities. Their responses has been to double down and create even broader spaces going from small groups to alternative social media, and I think, eventually an alternate society and political system. At that point the legitimacy of the US government will be challenged, and that's already beginning to happen, and we may have a civil conflict.

They've been creating smaller more exclusive communities for years. They have their own youtube news and fan/media channels, they have their own internet personalities and figureheads even among the mainstream (like dr disrespect, who seemed to be popular with right-leaning gamers I know), they tend to congregate in various indie games (especially war and FPS games), they have their own forums and online spaces (e.g. private discords; thedonald reddit clone, alternate subreddits; parler; 4chan, which is older than any of this but decidedly more right wing nowadays than I remember 10 years ago), and so forth. The problem is that they feel these spaces and communities are under attack. Parler, while I don't disagree with the right of FAANG companies to decouple from parler, is just the latest space that's "under attack".

This isn't unique to Parler, I've seen the right complain about this in gaming, movies and comics (like Star Wars), tabletop games, etc. for years and I know people who were otherwise apolitical but shifted to the right because they felt their hobbies and fanbases were being (unfairly) criticized and changed by outsiders specifically from the left-wing who don't appreciate the original characteristics. And I even agree to some degree that it's hard to have your own space without being attacked. For example, recently I am somewhat aware that Hololive idols, basically asian/japanese game and lifestyle streamers using 3D avatars, have been under (what I think is) undue scrutiny from some feminists for being sexist, pandering to pedophiles, and fueling misogyny. I've seen similar attacks on anime and on some games. Personally I think there's more of a racial element, given western phobia towards asians, in a lot of these attacks and criticisms because extra criticism seem to be targeted at japanese or asian media, but in any case, people on the right think it's mostly political and the political divide has not only worsened it's caused people to take sides and move from a localized feuds (fighting over media like anime and Star Wars) to a broader battle (politics, values, belief systems). And as far as I've observed, this tracks with their attempts and successes at creating increasingly broader alternative platforms. From having their own spaces within larger communities to creating alternative platforms, like parler, or hijacking sites like 4chan, and actually making them viable, unlike earlier attempts (like voat). As of January 6 I think we've come to the point where enough people have aligned politically on the right that they're going to want their own real world society, and not just an online one. Shutting down parler is just going to accelerate the sentiment imo, because as far as I've seen people kind of quantize their world views when (they believe) they're under attack, and group up. They don't become more understanding and broader minded, they become more tribal.

So if the right wants their own society just let them have it before internet fights become real ones. Personally I think it's still a small amount of people, my experiences are just anecdotal based on what I've seen in communities I was part of and people I know, but I think the sentiment is growing rapidly and trying to shut things down isn't working, at best it's a roadblock that pushes problems down the road, at worst it makes people go underground and become more competent at hiding in plain sight.

edit: My fear in particular is that they'll resort to wide scale political, maybe racial, violence. Not that they want right-wing spaces. I'm asian, a lot of us already kind of self-segregate and I don't see any issue with it to be frank. I know integration is important in the US but I don't see a problem with people wanting their own safe space where they're left alone, although it's sad it's come to the point where people attack the capitol.