The stated average transaction fee by OP (i.e $3) is not correct, it is around about 1 to 1.5 $.
Also he/she don't know about the lightening network as like many of the users, lightening network will going to make transactions much faster (in seconds or milli seconds) with low fees, this will make network much more efficient than ever before.
Both of these points have already been discussed in THIS thread:
https://bitinfocharts.com/comparison/transactionfees-btc-eth-ltc-dash.html#3mAccording to this chart, most recent AVERAGE transaction fee is $4.86. If this chart is not correct, please explain why or cite another source. Even if some transactions are .10, that does not change the average.
Regarding lightning network, it was posted above that the on-chain transactions is an amalgamation of off-chain 2-way transactions between the same 2 parties. But for a merchant who has many individual, one-time customers, the lightning network should not help?