Two questions addressed at the same time

Whenever someone raises a question about how security of bitcoin will be maintained when all bitcoins are mined, we answer it by saying, "In a hyper bitcoinized world, there would be enough transactions and miners would be paid enough with transaction fees".

Whenever someone raises a question about block size limitation and bitcoin handling only 7 transactions per second which is not enough for a hyper bitcoinized world, we answer it by saying "Bitcoin is only a core fulfilment layer and all micro transactions in a hyper bitcoinized would would happen in layer 2, like the lightning network".

Now how do we adress both together? I mean, in a hyper bitcoinized world after all BTCs are mined, if all transactions happen in layer 2, who/what would pay all the miners who ensures security of the network and who spends energy and adds the next block?