An argument could be made doesn't mean Hartline is better than Landry. That's not what it means at all. Not sure why you're lost.
Trade a player who's better than Landry, eat $7M in accelerated bonus money, pay him more than Stills, and depend on a 5'6", 170lb WR who has never been a full time player in the NFL to be a full time player in the NFL. There is no end to the Landry gymnastics.
https://media.tenor.com/images/45af3835a9e5daa6eaafd410b06bc505/tenor.gif
How can you not see that Still's and Landry's skill sets are completely different in what they bring?
Stills cannot navigate the MOF anywhere near the capabilites of Landry. Landry is the one who demands attention in the MOF to help rotate coverage off the top of Stills.
They are complimentary, not comparable.