I calculated for you how long it takes to clear those fights 99 times - if thats to much time for you, thats okay, dont do it then.
This isnt meant to cater to those people who cant log in every day. Things like the weekly lockout on drops and the tome-cap cater to those who cant log in everyday. I dont understand where you're getting the idea from that everything in the game is meant for people who cant log in every day, but I'm telling you: This is not. This is to keep people busy when they've cleared everything else and still would like to "have something to do". Its clearly not a mistake - its in place to get people to do those fights again and again, so new people have a higher chance to get their clears because people who have already cleared will go in again since theres still something left for them.
See it like this: With how easy the current EX-primals are (I hope we're getting more difficult ones down the line btw) they cater to casuals.
You go in there, casually try a bit, learn a bit, get your clear.
Thats the casual part about them - and then the game tells you "Hey, if you want more - there is more!" - but thats not casual anymore, thats an extra. A bonus.
You dont need to log in everyday to get that bonus if you want it. You can literally work towards that in your own pace. Get three tokens a day (around 30-45 minutes), be done in a month - get one token a day (10-15 minutes), be done in three month. You have the option to take a more casual approach here, it will just take you longer than a person who puts in 3 days of farming.
If you have such an issue with those rewards requiring some effort, you best forget that they exists... they're their to give vets an incentive to run this content again. They're their to keep this content alive and people busy. They're not their to please casuals - plenty of other content is.