I think differently.This is a classic generation thing, like we've seen in Tennis and Australian cricket after the 90's team. There's few world class 25 year old strikers because the 1987-1992ish generation took all the best jobs.
People define strikers by how they do for big clubs in big games, so you can't become a world class striker if City have Aguero, Barcelona have Messi and Suarez, Bayern have Lewandowski, PSG have Cavani, United have Rooney, Madrid have Benzema and Higuain. There's not positions left at big CL clubs to look or become world class.
Instead we have a generation who haven't quite lived up to their potential or are late bloomers because they got stuck behind the previous lot and didn't get game time. Werner, Jesus, Correa, Dybala, Andre Silva, Icardi, Morata, Alcacer, Martial etc. Now all regarded as not quite good enough.
It's probably a product of the big clubs having ever increasing money to buy up and comers as soon as they show promise and park them behind a world class striker.
A lot of that 25-30 year old generation got bought up at 18-22 and put on a bench, instead of getting to play and improve through their early 20s and become world class.
But now there's going to be a generation of players who come of age just as the 1987-1992 lot are finishing, and they'll take all the top positions at the top clubs for a decade.
The paucity of strikers now a days is due to pep effect.
Now a days clubs play the style more of a tiki taka. Even the defenders are judged by the way they play the ball from the back (Forget the hard core defending of before 2010). Its more of a midfielders game now a days. Defenders are midfielders(that started with macherano playing as a CB), Strikers are midfilelders (eg: Sterling, Salah, Mane, Firmino (plays like midfielder), Messi,) Recently strikers are playing as midfielders like gabriel jesus or in some ways ferran torres used as a striker. As a result v v few players are left as a top class strikers. In fact we can count in fingers ( Kane, vardy, ronaldo, Benzema, Aguero,Lukaku). Clubs used to have 3/4 or 5 top class strikers. (We used to have ba;otelli, aguero, tevez and dzeko). Now a days clubs have a maximum of 2 strikers.
This is due to the style the whole world plays. That is a pep effect or we can say barcelona effect or tiki taka effect.
Even managers who follow old fashioned plays like mourinho, Ancelloti, Mark hughes, Sam allardice, in some extent solskaer as well are finding difficult to implement their styles. Now a days klopp, Tuchel, brenden rodgers, Pochettino, that brighto manager, parker are best managers.
Well everything doesn't last forever. May be some part of the old days (as styles/pattern are repeated, very few are born) will return and then strikers will blossom. I think those days are too far. I see football going towards false 9 rather than typical nines.