To the topic I think Kerr is right, he need both the titles and to run faster times. He has a second and third from the olympics, which is extremely well - but you normally need a gold medal, if not your PR and results from other championships must be really well.
His best 1500 time is 8th all time, which is good, but if we dig into it, two of his contemporaries is ahead of him there and one is right behind him. This is further underlined by him being third fastest in 2024, 8th fastest in 2023, 9th fastest in 2022, 4th fastest in 2021, 15th fastest in 2020.
When we look at world championships we see that he indeed is world champion of 2023 despite being the 8th fastest that year. That gold is really putting him forward as the best runner in 2023 despite his slow time. However, since he is aiming to be the best 1500m runner of this era, his 5th place in 2022, 6th in 2019 isn't supporting this. Even when looking at other championships, it isn't a strong card for him: 12th at the commonwealth games '22, 10th at the U20 champs in '16. He won the european junior champs in 2015, but have been a no show his whole senior career.
When it comes winning at the circuit his largest win stream seems to bee three wins if we remove preliminary championship rounds (azusa bryan clay invitational, ncaa div I, albuquerque mountain west championships) - this was in 2018.
He has a world best in 2mile (i), european record in the indoor mile, and the european record in the 3000 (this was later bested by George Mills, and is 14th on the global list).
His head to head against contemporaries is:
3-3 Yared Nuguse
5-3 Cole Hocker
3-14 Jakob Ingebrigtsen
5-7 Jake Wightman
Summary:
Since he is the 8th fastest all time, third fastest measured against other runners in his era (if measured after Timothy Cheruiyot), have no olympic golds (still, silver and bronze is extremely good), one WC gold, have almost no presence in other championships or on the circuit, he indeed need to have more titles and run faster times.
Runners that is "forgiven" for their lack of speed usually have 5-10x as many gold medals as Kerr have (Mo Farah for instance have 5 european golds, 6 world golds and 4 olympic golds). Chances are slim, he could win a handfull of championship golds the next years which obviously would put him there despite his speed. He could also be able to consistently be the fastest 1500m runner for a few seasons and even set a WR, or a combination of those.
But right now he is one of two winning gold medals in the WC, not one of the two who have won olympic golds in the 1500, and have never been the one with the year best in the 1500. This puts him ahead of Wightman and Nuguse without argument.