Why aren't Bluetooth 5.0 adapters sold?

Question

Bluetooth

The latest current BT standard is 5.0
In the last year's phones and wearable devices, it's mostly it.
And the advantages of the description compared to 4.2 are significant.
But it only works if both devices support it. If not, it works on the bottom.
(I read all this from the Internet)
I am looking for an adapter for a computer. And I can not find
Yandex markets, and dns / citylink filters - everywhere 4.0 limit.
found on aliexpress. But there in the comments almost everywhere they say that all the same 4.0, not 5.0, as in the description.
In general, the question is where to find 5.0 and why they are not there (

Answer 1

Much confusion has arisen around Bluetooth specifications and versions due to the presence of two incompatible standards under the same brand, both of which are widely used for different purposes.
There are two different, incompatible Bluetooth protocols: Bluetooth Classic and Bluetooth Low Energy (LE, aka Bluetooth Smart). There is also a third protocol, Bluetooth High Speed, but it is not common and is not used in consumer devices.
Starting with Bluetooth 4.0, the changes to the specification were predominantly Bluetooth Low Energy, with the Classic version receiving either little or no improvement.
List of changes between Bluetooth 4.2 and Bluetooth 5:

9 CHANGES FROM v4.2 TO 5.0
9.1 NEW FEATURES
Several new features are introduced in the Bluetooth Core Specification 5.0 Release. The major areas of improvement are:
• Slot Availability Mask (SAM)
• 2 Msym/s PHY for LE
• LE Long Range
• High Duty Cycle Non-Connectable Advertising
• LE Advertising Extensions
• LE Channel Selection Algorithm #2
9.1.1 Features Added in CSA5 - Integrated in v5.0
• Higher Output Power
Only one change has been made to the Classic version as part of the Bluetooth 5 specification: Slot Availability Mask (SAM) technology has been added to improve air separation . All other changes affect only Bluetooth LE (and Higher Output Power too).
All audio devices use only Bluetooth Classic. Headphones and speakers cannot be connected via Bluetooth Low Energy: there is no standard for audio transmission using LE. The A2DP standard, which is used to transmit high-quality audio, works only through Bluetooth Classic, and there is no analogue in LE.
Conclusion - it makes no sense to purchase audio devices with Bluetooth 5 just because of the new version of the protocol. Bluetooth 4.0/4.1/4.2 will work in the same way in the context of audio transmission.
If the announcement of new headphones mentions doubled range and reduced power consumption thanks to Bluetooth 5, then you should know that they either do not understand themselves or mislead you. No wonder, because even manufacturers of Bluetooth chips in their announcements get confused about the differences in the new version of the standard, and some Bluetooth 5 chips support the fifth version only for LE, while for Classic they use 4.2.