• Google Maps: Switch to CoMaps, they're a fork of Organic Maps that grew out of a transparency issue with the Organic Maps core developers
• Youtube on pc: Not familiar with youtube-tui with mpv but FreeTube is pretty awesome too :3
• Clients for offline music: I like kew (for PC) :3
• Discord: Element is good, but in the interim you should check out Equibop! It's a fork of the Discord client that strips out a lot of the telemetry.

And regarding PeerTube, be aware that if you go into it expecting it to be a replacement for YouTube, you will always end up disappointed. YouTube is just too big and entrenched at this point and it's just not possible for any site to be a straight-up 1:1 replacement.

It's kind of like renewable energy sources: no one method is going to supplant fossil fuels, but multiple different options being used where each is effective the most has worked quite well in putting a quite noticeable dent, even if not a large one, in the world's usage of it. Likewise, PeerTube, Odyssey, Nebula, all the different sources cropping up will never replace YouTube individually, but collectively it will give people more options, which is always good.

Likewise, I've found that PeerTube is great for discovering new content, but it requires a perspective change. Honestly it reminds me more of YouTube in its early days. Not a lot of high-cost productions, but more just regular people putting up videos because they have a passion for it and want to share that passion. For now, I still do use YouTube, but I am finding some great stuff here and there on PeerTube as well. I guess what I'm saying is PeerTube cannot be a replacement of YouTube, but it can be a supplement to YouTube, if you want it to be.

Anyway, sorry for the ramble. Haha. Have a great day and good luck! ^_^

EDIT: Markdown syntax.