If blocks are mostly empty and miners are not confirming 10 Sat / Byte and under fees because they choose to not accept low fee txs than another miner will come along and include those low fee txs as there is an incentive to do so.
If a fee market doesn't exist than there is no one paying a premium for priority block inclusion and much less is collected in fees. A fee market is precisely what allows lower fees to be included at a later time and higher security for those who want priority.
1. yes another miner will come along and include those low fee tx. but that other miner would need to have adequate hashpower to win the race too
2. again theres no need for a fee market this decade
3. making a block capacity scarce does not = causing a fee premium. pools as you already said could choose to include low fee's because they see othr pools include high fee's.. pools can pick anything they like.
they do NOT need to fill a block. they could happily make a block with just 10tx of $1 each until peopl cotton on to pay $1. again you dont need to fill a block to make a pool only accept $1 fee's..
4. WHEN pools start caring more about fee's, THEY will adapt. but that is not any time soon
think about the economic lunacy of excuses core devs use just to tempt people to deburden bitcoin to use ln
left hand: paying $1+ to make 1 transaction a day is perfectly acceptable
right hand: paying $30 a month internet bill is unacceptable