I might be a bit obsessed when it comes to gathering information -video documentation and hard facts regarding different runners´ actual progression - to judge if the narratives promoted on these pages are true. In this case the narrative that Jakob has rather poor speed compared to other top runners.
I must admit that I get trickered by people like you and other negativists who are unable to see the real world through their biases glasses. If you consider this an insult then watch the videos on my above post and come back to comment with some substantial arguments and not some hand wavering ones. If you know the difference.
You don´t get it about about Jakob´s 800m ability. He was world class from 13-16, including having an age WR at 14. He also ran a fast 800m at 19 and since then he hasn´t run a serious 800m.
His 800m results were based LONG DISTANCE training from around the age of 8. This training has been unchanged for about 15 years. He has only upgraded the mileage and the number of training session. I don´t claim that Jakob can be world class in the 800m as a senior. But I think he could have run 1:44 last year when he was in his 2000m WR shape, especially if he had had time to run some races beforehand. And I think he can go sub 1:44 in the 800m within some years if he stays healthy and continue to follow his training regimen.
You are also wrong about not being able to improve the 800m when doing long distance training. I have been writing about it before, also on this thread but here we go:
Apart from Jakob Peter Snell was a prominent example:
When he started with Lydiard at age 19 in 1958 he had just set a 1:54 PB in the 800m. Lydiard told him that - with his great speed - he could be a top 800m runner if he improved his endurance. As you probably know Snell then started doing marathon training with the other "Arthur´s boys" and 2 years later Peter had broken 1:50 and running low 1:49 going into the 1960 OG. Under the OG he set new PB in 3 out of 4 races and came out with a gold medal and a PB of mid 1:46.
Shortly after he started with Lydiard he had also participated in the NZ 10 km X country champs and placed almost last in the 60 men big field. The next year after one more base training period he placed 5th in the same X country race and one or two years later he won. So by doing marathon training he improved BOTH his 800m AND his 10km dramatically over some few years.
I could give you MANY more examples of runners who improved a lot in both the short AND the long distances by in the same time by doing endurance training. But I will only mention one quite actual example: Josh Kerr.
As you possibly know Kerr improved his HM time with almost 2 minutes from late 2022 to late 2023. From early 2023 to early 2024 he further improved his 3000m/ 2 miles substantially. And we are many who think he most likely also can improve his 800m and 1500m significantly this year (barring illness and injury).
I am looking forward to hearing from you when you have watched the videos I have linked to in my post above. It is about Jakob´s finishing speedcompared to the other top milers.