Because you generally have to be quite lategame to even consider going for collection logs, so it gatekeeps clues
#In regards to Clue QoLs
lucid viper
split steppe
Collection log ranks definitely should not have any benefits other than cosmetic and hiscores. Plenty of people, me included, also like clues a ton without caring about the collection log. Especially with current rank tiers, it’s a pretty monumental ask to get tiers in clog rank, and putting actual rewards behind that isn’t a good idea, and mostly just makes people do a lot of things they really don’t care about
tropic wigeon
There's no reason to remove existing features and lock them behind the clog tiers. If some benefits were to be added to the clogs, it would have to be new qol/benefits.
Also, as above mentioned, unless you're a dedicated clogger, most people in the early-mid game probably will have sub 100 clogs. I barely have just under 600 and I'm an end game player.
split steppe
I’m a late/end game iron with two megarares and I’m at like 800 something
And as mentioned, I love clues
lost pawn
As many have said about CAs, you can't have good rewards locked behind high requirements 🙂
95% of the rewards are Elite Tier CAs, which is beyond easy now that Master/GM CAs count towards Elite Tier and many of those higher tier CAs are misplaced.
frozen drum
From your (OP) point of view, why not make this connection more direct?
Why collection log ranks instead of clue ranks? (https://oldschool.runescape.wiki/w/Treasure_Trail_Statistics)
lucid viper
95% of the rewards are Elite Tier CAs, which is beyond easy now that Master/GM C...
the up to 2min thrall timer is kinda good though, saving quite a few prayer points extending trips
lost pawn
It's pretty minor compared to double cannonballs, clues, 25% more common superiors, bracelet saves, gwd instances, etc.
lucid viper
instances are hard CA though
lost pawn
Yes, 95% of the rewards are at Elite Tier, which includes the rewards below it 
Master/GM is mostly pet hunter perks, which isn't everyone's thing.
lucid viper
Turns out that GM has all the benefits of Elite tier then
lost pawn
okay then 🙂