Yes there is some janky stuff in TFT, some OP comps that are gonna be nerfed and so on, but at the very meat of the subject is simple
TFT is actually more balanced than SR.
Now we all know it's not perfect, but when you get down to it, every comp has a strategy, counter strategy and positioning or itemization.
Demons struggle against Manaless comps
Manaless comps struggle against Assassins
Assassins struggle against Bruisers
Bruisers struggle against Mages
Mages struggle against Demons
and so on...
When I play SR, first thing I see is there's always 3-4 absolutely busted Champs that are must pick or must ban, they often have no counter (the reason they're must pick or ban) and it often stays that way for months (not a single week in the Case of Ninja Assassins in TFT which has now fallen out of favor)
That brings me to my second point, there's no telling if it'll stay this way but pace of balancing.
Like I just mentioned, broken stuff in SR can often stay broken for months, in some cases longer before they accept maybe they got it wrong. Everyone told them that Akalis stealth needed to be countered by pinks/true sight, Riot wasn't having it so Akalis reign of terror lasted a pretty long time so when they finally fixed what they were supposed to, the rest of her kit is now less than it should be. They make questionable balance decisions which should never get out of PBE (Galio and recently Reneketon) and in general seem to think loading the game with "More damage, More CC" is exciting.....
No that's not exciting, it's frustrating and endemic of Meddler/GC's design philosophy that messed up WoW's PvP scene to the point that when they introduced Arena mode and wanted it taken seriously as an E-Sport, it got laughed out of the building, now this isn't to say WoW had "perfect PvP" but every class had their place and didn't feel entirely worthless. Right now, I sympathize with Marksmen and Bruiser players, the two consistent damage dealer types just feel entirely worthless and nothing showed that more than the fact we have slipped back into Mage bot lane meta again (Unsurprising given a certain leads obsession with Mages) and Assassins/CC bots in the Jungle/Mid/Top.
The more damage the game has, the less strategy is involved, the more CC it has the less strategy is involved, when people say SR has become "Stale" they aren't kidding, I used to get quite hype watching the big outplays in the pro scene, now it's just "oh look another pick where they were CC'ed to death or got damaged too much to react". Stalls are typically coming not because "strategy" it's because nobody wants to be the person engaged on because they're often dead instantly.
Playing TFT, the only time this'll happen is extreme late game if someone has an extremely strong unit, but there are actually strategies and counters to mitigate how much they can do to you, the only "unit" that feels useless really is Morde, but even he still has his niche (Being that Phantom is a very strong synergy) positioning is meaningful, CC bots are balanced by having low damage or countered by other comps and strategies (Demon burn/splitting your units up/ Yordles)
So yes, I'm much preferring Mortdogs philosophy over Meddlers philosophy right now, I hope he keeps up with the quick weekly balancing, communication and goals as TFT has me hooked, SR just no longer holds my interest and that's all down to balancing philosophy and implementation.