You are absolutely wrong.
1. The voice qualities are literally the same. Both are mostly using the same codec (OPUS). Teamspeak got some more, however they are not better and no one actually uses them. The youtuber "linus tech tips" did a video about it where he compared the audio. You can't hear a difference. He even linked the audio files in the description, check it out here.
https://www.youtube.com/watch?v=VayvZUL2mBc&t=249s
2. Let me quote discords privacy policy: "The Company is not in the business of selling your information". They also don't need to, it would probably hurt them more (because their reputation would go down) than it would help (selling data without showing ads on their own page is literally not a good business). Their main incomes are from cosmetics (nitro) and other services they offer in addition (their store).
3. The entire community runs over https. This means you, discord and the recipient can read the data you send. Teamspeak might have a slight advantage here because you can enable end2end encryption there, however many people don't do that and your claim that there is no encryption at all is still wrong.