I think the per Byte calculation is confusing for beginners (it is to me), and also unhelpful in understanding/estimating transaction costs. To answer the question 'how much BTC will it cost me to send 0.15 BTC to my friend?'.
Some explorers usefully provide the total fee. For example in
https://www.blockchain.com/btc/block/000000000000000000092072d35d34e3cf35c26c18bb468e99ad6babcff07b4dFee Reward 0.12328166 BTC
Transaction Volume 4846.03749344 BTC
This means the fee paid is (100*0.12/4846.04) =
0.002544% of the transaction amount for this block. (Assuming that the volume does not include the fee - please correct me if there are any other wrong assumptions in the calculation).
Has someone calculated the total of this for all blocks? If not, can the techies here run the calculation or show me how to get the raw data (I only know Excel

)
Would also love to see these important data points from this analysis:
1. How the transaction fee % is changing over the years.
2. The transaction fee % for smaller transaction amounts which are the majority of transactions (as transaction size does not impact the fee, so larger transactions skew the % down).