I think it's somewhat related. The French social security site has a page asking phamacists to make sure the prescriptions are correct, in order to guarantee availability to people who actually need this [0].
This sounds pretty much like the supply is somewhat limited for whatever reason.
Also keep in mind the processing time. The ^ article above used a NVIDIA L4 with 24-GB VRAM. Sopro claims 7.5 second processing time on CPU for 30 seconds of audio!
If you want to get real good quality TTS, you should check out elevenlabs.io
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