You answered your own question.  Lighting, custodians, fedminits, stuff not yet invented is what will happen when it’s $100 equivalent per transaction. 

Normal people already hold checking, savings, credit cards, brokerages, HSA, Venmo, etc accounts. In the future they could mix a custodian lighting wallet for checking, a custodian L1 / Fedimint / whatever for short term savings, and cold storage self custody for retirement. 1 solution should not meet all of these needs as they are different. 

Necessity breeds invention. Bitcoin already transacts as much as Fedwire and its open nature means it should be easier to verify your funds with a custodian than the current black box of fractional reserve banking. Not saying it shouldn’t ever change, but the barriers being so high is a good thing. It means there needs to be a real problem to solve instead of hypotheticals in the future.