Scalability Discussion ( and a word to the core developers ;) )

Hello dear bitcointalkers,

I possess BTC since 2012 and I try to watch and understand its development.
Yet, about the scalability and block size discussion, I don't understand the arguments, especially not those from the core developers.

I want Bitcoin to be a "A Peer-to-Peer Electronic Cash System", just exactly like Satoshi Nakamoto's white paper title stated.
I dont want Segwit or side-chains as they just distort the scalability solution.

I want to express my opinion (if Core-Developers read that, please):
Keep things simple!

Scalability ain't that difficult.
Think of, how U would like a p2p-cash to work.
Think of, for example, a variable block size, collecting all the Transactions.
Big Transactions cost more fees than smaller ones. etc etc.
Create one security paramater which assures/limits that the total amount of transactions per time unit (in BTC or EUR/$ worth) is covered by enough mining/computer power.

Don't turn into nerds and develop things, noone wants, making future code developments just more complicated.
The current step is to make Bitcoin practicable and userable for all kind of transactions word wide.