Then you probably don’t know any better because the vast majority of YT uploads are terrible quality. If you have anywhere near decent headphones/earbuds you can hear the difference immediately.
Well if you save the opus or aac it’s only single lossy compression, not double unless the uploader used a lossy file as their input. But if that was the case, ripping mp3 would be triple lossy compression…
The combat becomes much better when you gain some levels. Early you only have few spell slots and cool bonus actions. I can assure you it gets better the longer you keep going, especially if you loot all the usable consumables (scrolls, arrows, etc)