Kindle Vella is an insult to readers, and a mistake for BCTS

MIcrotransactions of the very worst kind, with no more guarantee the novel will get completed, than on a free site.

Worse it's an awful attempt from Amazon to replace the free sites like BCTS, with P2R> (Pay To Read Next Chapter) content.
Just Like Kindle Unlimited was an attempt to replace Public Libraries lending Digital copies of Books they have bought, with a subscription service.

No surprise this is restricted to USA on launch, as that country is far more likely to accept P2R> content than the rest of the world.

The reason we are willing to accept that BCTS novels (or novellas) may never be completed. and let's be honest there's more incomplete novels here, than completed ones, is that on top of it being a very niche site, the content is provided for free by the authors.

Kindle Vella FAQ extracts

1. What kind of content should I publish?
To provide the best experience for readers, Kindle Vella stories should be written specifically to be released in a serial format, one 600–5,000 word episode at a time. If you have a story in this format that is available elsewhere, you can also publish it with Kindle Vella. To ensure a good customer experience, Kindle Vella does not accept content that's freely available.

3. How do I earn royalties through Kindle Vella?
You earn 50% of what readers spend on the Tokens that are used to unlock your story’s episodes. You’re also eligible for a launch bonus based on customer activity and engagement. To make it easy for readers to find stories they love, the first few episodes of every story are free. The number of Tokens needed to unlock an episode is determined by the episode’s word count at the rate of one token per 100 words. Tokens cost $2=100 Tokens, with the typical bulk discount, rates $10=1,100 Tokens.

TLDR:
To force the mark ("ContentConsumer") to pay for your pre-existing content, remove ALL free copies, and sell the same content as microtransactions instead.
Basic cost is around $0.50 per 5,000 word chapter, and unlike the normal Kindle split of 70% for Publisher (or Author), 30% for Amazon, this is a 50%/50% split.

To see BCTS promote a service intended to replace all such free sites, is really disappointing, sure just like with Kindle Unlimited the site can keep it's Standards with DopplerPress, but nothing stops ANY author from cutting out the original site/publisher entirely.

I will never pay subscriptions for what should only be provided by Public Libraries Digital Lending Services (Kindle Unlimited).
I have never supported microtransactions in gaming, and refuse to play (or buy) any game that sells them.
I will now refuse to read (or buy) microtransactions any fiction either (Kindle Vella).

Play/Read (or Buy) means
I don't even consider microtransaction infested content worth pirating.
Your content simply ceases to exist for me, the moment you added microtransactions.
Even if I already owned it for years, like with Fallout 4, Skyrim SE, add microtransactions, and I remove that content from my life forever.

This is a depressing start to my day