Where are you getting "only earning half the tokens for the same number of games played" from? Games are 29 minutes on average and according to your no source math you need 34 minutes for 10 tokens
No source? its literally in their own FAQ, you get 6 points per minute for a win and 4 points per minute on a loss on SR and ARAM
https://www.leagueoflegends.com/en-us/news/dev/quick-gameplay-thoughts-12-3-event-mission-points/
ARAM and Event Game Modes grant 4 points per minute played, or 6 points per minute played if you win. This includes game modes like URF, One for All, and Ultimate Spellbook. In other words, these will grant points at the same rate as PvP SR games.
So yeah its 33.3333333 minutes for a match rounded up to 34, so if you want to be pedantic about that knock yourself out
you are getting like 7% less tokens which is around 30-40 tokens assuming you get around 2200 tokens per pass (including the mission tokens).
Because for the same number of matches played, you are going to be averaging less
If i win 2 20 minute games of SR and thats all i can play for the day i've earned 10 tokens instead of the 20 i earned before, not everyone can dedicate maximum hours to playing league
So now lets assume you play 100 games in the month with a 50% winrate and use the average game length of 29 minutes
Previously you would earn 750 tokens, 50 x 10 and 50 x 5
So for 100 matches of an average of 29 minutes each you will earn 8700 points for wins and 5800 points for the losses for 720 tokens, which would match your number
My games don't tend to average 29 minutes as i mainly play ARAM, which is a substantial nerf to the amount of tokens i would earn as a 20 minute win would give me 6 tokens and if we assume i can do 3 matches in the same time 2 average length matches complete i earn 18 tokens for 3 wins compared to your 10 tokens for 2 wins
So yeah not quite half but i would call an extra 80% a not insignificant amount of tokens
So yes for the SR only players they probably won't notice as large a decrease for time spent, but for ARAM players thats a massive hit