...but I agree with the part that "from an economic point of view, grin is the same as dogecoin"
Grin has constant block reward. In Doge the current reward is only 1% of initial reward.
Not quite the same, unless your only distinction is capped vs uncapped.
Taking that to an extreme, Grin would be the same as Bitcoin with a 1 satoshi tail emission,
where late miners are rewarded 5 billion times less than initial ones.