Correct, the fees would decrease, but when when you can only process 200k transactions every ten minutes, there’s an upper limit of how much people are willing to pay before it becomes absurdly expensive. This reached almost $100 in the 2017 rush. It’s unsustainable and renders the network unusable for most of the planet.

When you on the other hand can process millions of transactions every block (and scalable as needed), you’ll charge far less per transaction while still allowing miners to generate a huge (and ever growing) revenue, while also enabling most of the planet to transact next to free.

From an environmental perspective, if you divide the hash rate environmental impact on a mere 200k transactions every ten minute, the carbon foot print per transaction would seem absurdly high. Do the same calculating for millions of transactions every ten minutes, and you’ll arrive at a far better environmentally friendly figure.