Another great indie soundtrack is Death Road to Canada's.
I see you put Hades, haven't played it but I can attest that Supergiant's first game Bastion also has a pretty good soundtrack.
I love the minimalistic soundtrack of Baba is You, made by the developer. Almost all filtered saw waves so it sounds "chippy", but I dare anyone to port it to the C64.
FTL is an indie game which does cinematic soundtracks right, in my opinion. The chip elements are there, it's definitively not chip or tracker-style but it's still very good.
But there are bad indie game soundtracks too. Honestly, Slay the Spire, while a great game, has exactly the terrible cheap wannabe cinematic orchestral soundtrack OP complains about. It's at least slightly better for StS 2.
https://www.youtube.com/playlist?list=PLD6ujQ0tHAv2qLS5FKH6B... - chopped beats, glitched words, everything you would expect in a love letter to Jet Set Radio
https://halberball.bandcamp.com/album/fragrance-point-soundt... - absolutely perfect noises for a game that looks like a 90s rave flier
https://supergiantgames.bandcamp.com/album/hades-original-so..., https://supergiantgames.bandcamp.com/album/hades-ii-original... - hades and its sequel shifts seamlessly between lutey-flutey strumming, hard rock, ballads, and sets the heck out of its mood
https://momojams.bandcamp.com/album/flipwitch-original-game-... - this horny metroidvania can fit so many electro-swing bangers in it
https://blackpantsgamestudio.bandcamp.com/album/tiny-big-sou... - sideways grooves and gloriously self-indulgent prog
https://polybius-ost.bandcamp.com/album/polybius-the-origina... - so much blissful techno to stare fixedly at blinking lights to, while the Welsh wizard who wrote it repeatedly insists that you are not being programmed by this experience in any way