There is no reason why bitcoin can't be the all in one package we all want it to be someday but right now there is not enough demand to support the network with low fees.
We should only raise the block size in minuscule increments to keep fees high enough to support a robust mining community.
I like your point.
Except that right now the network should not be supported by fees but by the block reward.
Your missing my point completely transaction fees + block rewards are more or less = to the amount of money reinvested in hardware to mine bitcoins. As the block rewards drop in these massive chunks every 4 years so dose the amount we as a network spend on security. Let me be clear Block rewards account for the majority of this and with each halving day we lose more or less 50% of our network security. The fees the network gathers today are virtually worthless some miners don't even bother processing transactions because its not worth their time.
I already explained that we do not lose fifty percent of our security at the halving, since the exchange rate also effects this dynamic, after all security was not reduced after the last halving. It would only take sixty times the transaction volume we have today to match the block reward we have as well, this can take a longer period of time since we do still have a block reward subsidy in place to bootstrap Bitcoin for the next few decades, we do not need to sacrifice all of these use cases and characteristics of Bitcoin to pay for security, it is exactly these use cases and characteristics of Bitcoin that will pay for its security going into the future.
It costs less for an attacker today to conduct a 51% attack then it would have 4 years ago. You see hardware becomes cheaper and cheaper but as the block reward drops so dose reinvestment. Soon we well reach a plateau were miners invest less and less and at the same time hardware will continue to advance, hardware that's forever cheaper and cheaper. Its under these conditions of low reinvestment and antiquated hardware making up the majority of the network that will allow for a governmental agency or disgruntled corporation to come in with a relatively small amount of money and blow this house of cards down. A irreversible block increase now would most likely devastate the network in 8 years. Since we can't predict the price nor the demand for bitcoin in 8 years we should do the prudent thing and position the network for a very long and slow growth curve lasting decades.
I am not even advocating a long and steady growth curve, I would be fine with a simple increase to two megabyte and then adjust again as needed, I think that BU best accomplishes this goal. It is absolutely not true that a fifty one percent attack cost less today then it did four years ago, back then asics where not even being used so comparing the hash rate and the costs involved are worlds apart.
Antiquated hardware is unprofitable and just ends up being scrapped, furthermore old hardware is not as powerful either. It is not the case that a government or corporation could easily come and commit a fifty one percent attack, it would cost a lot of money, and as adoption and the price increases this will cost even more money. I am a miner myself, and it is not becoming cheaper to be a miner, technology keeps advancing and as a miner you need to keep upgrading and cycling these machines in order to keep operating profitably.