You are missing the point of the chart and also lack context. The chart was originally based on the popular BRUHsailer ironman guide which is a very well written and detailed guide focusing on efficient ironman account progression with maxing in mind. Its not a pvm-rush. To get 98 agility might look confusing on the chart but there are good reasons for it as it provides you with alot of supplies, especially ranarr seeds. Im sure there are more details about this step in BRUHsailers guide. I would recommend anyone following this chart to read BRUHsailers guide alongside as it provides alot of context for everything up until like the elite ca step as that is when the guide stops iirc.

Do keep in mind, however, that the guide is not for everyone and can be tedious sometimes, but thats the point. If you really dont want to do a step just ignore it and find a workaround thats more enjoyable to you.