Okay, let me state right off the bat that I think Tonyan is a very reliable and good tight end. That being said, the guy averaged 36.6 yards receiving per game, which was good for 15th among tight ends last year, which isn't what I would consider a "breakout". In 2019m that 36.6 yards per game would have been good for 13th among tight ends and would have been 16th in 2018.
I am NOT trying to say that Tonyan is a bad tight end, he's a very reliable tight end that will get the yards Rodgers gives him but he won't get much more. That's perfectly fine. I don't think he's become a player that Sternberger cannot overtake. Now, I don't think Sternberger WILL overtake him simply because Tonyan is more athletic and, at this point, obviously a better route runner and receiver. I also do not think the Packers currently have a top-10 tight end in the NFL, though I hold out hope that Tonyan might be able to improve his tackle breaking ability and become a more dangerous receiver.