nothing about bitcoin is complicated unless you want to make it complicated for yourself. the case of decimals and number of zeros is exactly like the case of saying they don't understand how bitcoin works.
nowadays people don't even want to understand how things work, they are only using them. it is the consumerism at its best and you can't do anything about it. for instance when buying something you don't care if it has no zeros or hundred zeros in front of it, you don't also care how bitcoin works you just point your phone at that picture which you may not even know is called a QR code and click confirm and make the payment. or if you are on PC then you just click on a link and the payment happens after you confirm it in your wallet.
There are already a lot of apps in development for the lightning network, very easy to use wallets in which you scan a QR code and that's all. As a matter of fact someone made a very cool coke dispenser which works on the LN mainnet:
https://www.youtube.com/watch?v=2Fb6Xww2P7cThere's also others with coffee and whatnot.
But the conversation here is the unit of value being too high compared to what people is used to ($1, 1 or whatever local currency you have). And yes people obviously care about number of 0's when buying stuff. This is only solved with time. BTC must become the unit of account so people think in terms of BTC and not in fiat. Until then the price fluctuation will be there. The good news is you can get very rich by holding since it's already a better gold.