I've been in this (hi-fi) hobby enough to say that companies' money doesn't change much when audio quality is the main point. Apple and Sony will put their efforts on features, others will aim for audio quality.I dont think the connection is the weak point, up to a limit. The Pi7 and Nobles actually sound really good, wired or not, so they prove that even within a wireless limitation you can produce an iem that sounds great. The other sub par tws are not a sign of codecs but likely the acoustic design. Thats why its possible that Apple, who now have more money to dump into iems than likely sennheiser & campfire audio combined, owing to their absurd airpod profits, could make something special.
Bluetooth actually is a bottleneck, I've been having connection issues with both PI7 and XM4 (PI7 mostly).