Necas is, and has always been, a much better player than Frost. I don't think anyone here would argue differently, so saying that Frost isn't a top 6 forward because he's not as good as Frost is misrepresentative.
Necas has a 70 point season under his belt at age 24. He's got 20 points in 11 games so far this season. If you watched any Carolina games other than the 3-4 games against the Flyers, you can clearly see the talent level of Necas. He's always been a supremely talented player, he just hasn't always put it together when it comes to the scoresheet.
Below is his goal threat presented by Hockey Viz. You can see he's always been an above average finisher and passer. This year is not on this figure, but it's aligned with his abilities from his 25 year old season.
View attachment 926977
Here's his player card from 23-24:
View attachment 926978
Here's his player card from 22-23:
View attachment 926979
Here his player card from 21-22:
View attachment 926980
So, I'm fine if you want to scrutinize Frost. He's not been particularly great at the beginning (he's also not been nearly as bad as you're letting off). But, let's stop comparing Frost to legit top line players because that's not fair to begin with.
The Flyers wabsolutely got there asses handed to them, and only kept the game competitive because of two lucky bounces. Total shot attempts were 86-36. That's not competitive. The unblocked 5v5 shots looked like this:
View attachment 926984
Here's something where I actually agree. I think the Flyers are trying to build a team like Carolina. I think they want that aggressive, up-tempo style. But Carolina is built from top to bottom, not just the roster - the entire organization, to do this. From drafting to NHL scouting to coaching to the players, the Carolina team operates differently. Carolina would have never signed DeLo. They would never have signed that Hathaway contract extension. They wouldn't have signed Tippett to an 8 year deal. They take advantage of dumb teams all the time -- that's why they are so good.
I'd also agree that Carolina doesn't have 'superstars', but they have 3-4 forwards who are capable of scoring at a ppg, and the best supporting offensive and defensive cast in the league. I don't know how you can just hand waive the amount of raw talent this team has. The reason they can play so quick is because the entire team has an elevated skill level. The Flyers don't have anything like this in their prospect pool.