He was a legitimate nightmare to deal with in 2018. Great in the run game and great in the deep ball game (when the ball was delivered anywhere within a catchable radius...). You put 2018 Taylor Gabriel with a functioning offense and a good quarterback and he would've had unreal production that season. He speed and burst were on point, his route running was perfect, he worked the sideline flawlessly, he was physical, he made all sorts of outstanding catches.
He was off to a monster start in 2019. Guy had a four touchdown performance in week three against the then-Redskins, but then he got hurt and was pretty much scuttled. Now he is basically out of the league. That's how it goes in the NFL.