Now that the major tech companies have all removed Trump's accounts, finding alternatives simply aren't there and likely will take many years, if ever, to create - let alone be competitive.
Parler today just got added to the list of banned apps on both Google Play and Apple's App Store, yet another avenue cut off. The power of big tech wielding it’s weight is impressive to say the least! These are power companies in every sense of the word and just like PG&E or AT&T, when those go down, the lights go out.
UPDATE 1/9/2021
Apparently Amazon (AWS) was hosting Parler. It has now removed it from their servers. Wow.
UPDATE 1/13/2021
One of the arguments the GOP is making against Big Tech shutting down their social media accounts is that this will somehow drive the radical right underground. I would argue that's specious at best, the underground is already there. What it most certainly will do is make it much harder for Trump and the GOP to communicate to their base. How could it not?
Arthur "Bomber" Harris called the bluff to a similar objection in World War II to carpet bombing Germany regarding the efficacy of British air power to end the war. In that case, the British went forward despite the outcries to fire bomb German cities and civilian populations, most controversially the raid on Dresden which cost thousands of civilian lives. Their cities and factories destroyed after relentless Allied bombing, Germany lost.