Having started my career making military radars, I've always been amused by tourists that criticize the cost of products that are required the have extreme performance and reliability in industries that are highly regulated to ensure compliance. The best simple explanation I've ever seen for the seemingly excessive cost was from an episode of West Wing:
It's important to note that these improvements only apply to BLE. Classic Bluetooth (EDR) is not changing, at least not significantly.
Also, there will continue to be minor spec revisions (5.1, 5.2, etc). The "Bluetooth 5" terminology is for marketing and PR, to simplify the message. They don't want to confuse the general public with spec revisions.
https://youtu.be/7R9kH_HOUXM
While an ashtray may seem trivial, this example shows that in life-or-death situations, every detail must be considered and doing so is not cheap.