Personally disagree, SBC is pretty obviously bad and AptX isn't that hard to hear either IME. I would say LDAC and AptX HD are pretty close to transparent, or actually transparent, though.
I agree, Ldac above any other codec offers an audiophile level listening experience. sbc and aptx are not on an equal footing (even in the HD version), but if you use them for non-critical listening they are still fine for most cases.
But if the OP's original idea was to have two speakers to be connected to the smartphone with the 3.5 mm cable, I doubt that he has needs for audiophile purity, and therefore probably for his case, bluetooth is more than enough.
Let's compare price.
A good wired dongle via usb C cost less than $50.
My preference would be base on AK4377 DAC; if design properly it is possible with SINAD 108 at 10mW with 32 ohm load.
A quick search will show $35 from 7Hz.
My favourite IEM is the 7Hz Salnotes Zero costing $23.
Now, tell me the cost of upgrading to wireless, example a TWS.
It must have the same sound signature of AK4377 and the sounding of Zero IEM.
Personally I do exactly what you say, I use my own thrutear zero with a bluetooth receiver aptxHD is about 20 euros and I can combine the comfort of bluetooth with the quality of iem di buon levello, plus I can change iem and keep the receiver
But if you want something on the level of a good dongle I believe a product like the topoing bc3 can do the job, with a quality analogue output, volume controls and internal battery for around 70 euros.
For a few euros less there is the Hidizs with similar functionality
Bluetooth chipset in an audio device tends to raise noise floor so much that I can hear hiss from my speakers.
Hiss from my speakers is not acceptable. I sit close to my speakers.
I avoid anything that has bluetooth.
Bluetooth chipset adds a lot of noise to audio.
This may be true with cheap receivers (the one I have shown in the picture for example has a background noise that can be heard at low volume) but with better receivers and with ldac codecs it is no longer the case, my xDuoo x50 pro doesn't have the minimum background noise connected with the optical cable to my dac