Good luck to the creator. Pixelfed works well for me, despite being a bit empty, both on my instance and globally. The bones are there though and I personally prefer the way it works over Mastadon's Twitterish format. I wish I could use Mastadon more because that's where the mist fediverse users seem to be, but even decades later, Twitter style interfaces do not make sense to me. I'm a smart, nerdy, millennial, who grew up with computers. I can make sense of the IRS's 1040 form without using turbo tax, but for some reason I can't make sense of this horrible illogical interface that millions of people love.
In regards to the tiktok tok style app, I think it'll have a good chance of success simply because it is TikTok's less assholey cousin and even though many people will trade privacy for functionality, tiktok is about due to become a lame, cringe app for old folks.