Why Ashe and Varus in Challenger?

They have utility.

Even if their lane is camped and they fall behind, they are still useful for initiating fights and scale relatively well into the late-game.

hard CC ults

There are hard carry adc champions and then there are utility adc champions. Varus and Ashe both have cc ults,slows,and lots of poke. Play those champions for their lane harass and poke as well as team fight ults while other adc champions might look cool they are meh when it comes to the LCS.

Utility adc champions/teamwork > Hard carry ADC Champions/Solo Q that looks cool.

it is the start of the season, no one knows yet how well the meta is developing, they go for the safe choices on ADC with long range early and with CC or super long range late (Jhin, Ez)

These champs are not so good at the moment (except Jhin), tbh, when teams will figure out the meta and they'll have more confidence in avoiding traps and cheese tactics, they will slowly disappear or being back being niche picks

Both are extremely easy to play, and easy to use their kits to full potential.

Good utility for picks like everyone else says, but also they can farm multiple minions/waveclear from long range -- ashe volley can get multiple low hp minions from outside aa range, varus piercing arrow and hail of arrrows can do the same thing even better. This gives great harass, waveclear to stall/prevent enemy tower dives. And both of them can mess up an enemy team's attempt to tower dive via their ult -- locking the enemy under tower too long so they die tanking it. This also buys time for their team to come and counter-gank.

Both are utility, for starters. Varus has plenty of range, thanks to his Q (I think its longer than a Caitlyn Q but not sure), can provide soft and strong CC with his E and his Ultimate, and scales very well into late game. Ashe has plenty of CC as well with her E and Ult (Arrows op), but she also provides safety across the map with her w (Hawkshot I think its called?), as well as an autoattack buff on her Q. In the state where ADC's are relatively weak right now , both can provide relative utility with little gold and can take over a game if they destroy the opposing teams bot lane turret first.

Since its challenger and not solo-queue, teams are much more coordinated then those in solo-queue, so adc can now be a tool to support or aid the team rather than carry (see Vayne, Twitch, Draven, etc.)

Just my thoughts tho

Ashe becuase ulility and varus because he counters ziggs super hard in lane. This makes it so that with him open( which is likely becuase adc's are rarely target banned) the enemy cannot pick ziggs.

They have great Utility, that's why they are seen a lot in the LCS as well.

cc utility

Hilarious to go onto boards after some LCS and act like they have any clue on how to play the game, after watching pros, listening to some casting HILARIOUS

These champs are good in Challenger, but it won't mean they're great in lower elo.

Ashe offers heavy engage / utility.

Varus counters / does well against both S tier ADCs right now ( Cait / Jhin ) Also offers CC on R and his W is %HP damage for tank shredding.

Ashe and Varus are in Challenger. But so is Ezreal, Vayne, Cait, Jhin, sometimes Twitch. Kalista is making an appearance again, and ADC players seem to be doing well with her.

These are all for Challenger players though. They obviously have a very great grasp at their role and champion. So it's advised lower ranking players play something less mechanically demanding.

Like Sivir, Ashe, Jhin.