"technically" is not economically. I can theoretically move a mountain with a pick and shovel, in reality I won't.
The "technically recoverable" reserves is like saying there's technically recoverable oil in asphalt roads. Sure there's bitumen in that dirt but it's not "more and more", it's "less and less". Converting coal to liquids is technically possible. It's not economical yet. Running vehicles on waste vegetable oil is technically possible, it's not economically possible to run 10million diesel vehicles on it.

Defining reserves disregarding cost of extraction isn't a useful number. If your need is 10gallons of gasoline a week at only $2/gal it's kind of meaningless to say your local gas station has "lots and lots" if the rate at which you can fill your tank is only a gallon an hour. You can "technically" get your ten gallons. You'll just have to adjust your visits to the station to accomdate the ten hour time it takes to fill it. One hour a day and five on the weekend? Ten hours on the weekend? That's the problem with the new sources, they cost more and the total production per day is LESS than prior discoveries.