The remote phosphor technologies will help with lumen maintenance, as the dies do run hot, and degrade the coating on them with time. There is a place for them, and a place for incandescent as well. Incandescent is well suited for high temperature applications where they are able to run up to the softening point of the glass. LED and fluorescent is suited for areas that do not exceed 50C at the lamp surface at peak, and are a poor choice for enclosed fixtures.
The major killer of linear fluorescent is the green label, as the tubes are dosed with a critical amount of mercury, and as they age the mercury is adsorbed into the phosphor and the glass. You need more than 2mg of mercury in the tube, and cutting the amount down is the killer. Full mercury tubes ( 6-8mg inside) are made on the same plant and with the same technique and material as the eco tubes, which are pretty much going to fail within 2 years, while the full mercury units will run for nearly a decade before failing due to rising electrode drop as the cathodes are stripped and ion burnt. The low mercury will fail and glow pink due to starvation long before the cathodes are worn out. I buy the full mercury tubes, as they last longer with better lumen maintenance. Much better to have a single 6mg tube than replace 5 poor tubes in the same period. Mercury is not an innocent metal, but then again neither is LED manufacture, using toxic metals like Gallium ( similar in properties to mercury) and Arsenic in the construction.