Right about most things.
Except the fact that Smartphones hardware changes. New Processors, New Optical Sensors in the Cameras, new SSD's (with higher capacities and faster speeds)
This is especially going to keep going as Qualcomm is about to step their toe in the Desktop market, essentially giving them potential increase in market share for Laptops.

Giving them opportunity to invest more in making efficient processors that could improve future phones.

Things that are missing from all Smartphones today are
- 2TB+ Storage (already possible with m.2 ssd's about the size of an SD card.
- gpu's capable of handling all the Mobile Ports companies have been bringing to the market (lot's from China here) rn setting things to max graphic settings is just not feasable for prolonged time (given battery consumption and heat).
- AV1 encode/decode (this is very important for the next 2-5 years for everything video playback/production)
- Bluetooth (will probably see upgrades past 5.3 aka LE) within a few years
- better wifi chips (come out annually so there's always improvement)

Nyquist theorem has been put into question more recently iirc.
DSD for one showing some ABX test results to not be entirely conclusive.

But the community probably spending +500% that of average audio listeners cares about sampling rates and such. So maybe it would make sense to still make sure people actually release in high quality.

Some Soundcloud artists only have Mp3 LameV3 320kb/s releases and it really pisses me off to add them to my otherwise flac/DSD collection

Deezer, tidal and qobuz already exist for that. Yet they use 16/44.1 and some releases are compressed for the Loudness war's sake.

Spotify is also definitely not moving to Lossless anytime soon.
They have no reason to, most people who use it, do so for the Algorithm and the ease of access. Those that care about the quality aspect have already switched or use something besides it for actual playback. That being said, I hope they consider at least flac 24/48 at some point in the future.

If Deezer can optimize their recommendations and add a bigger catalogue, they might be more competitive and therefore force Spotify to up their game.

Idk. Planar designs seem to make big waves recently