I guess riot just doesn't get why league was popular back then and why it is dead now. There is no point of playing TFT because there is no doubt that none of the issues that are rampant in their main game will be fixed in their auto chess rip off.
1. Removing skill as a factor from the game. Dota auto chess takes way more skill and normally the better player will win even with how RNG infested it is. In pub matches I get first place 90% of the time. In TFT, positioning matters far less and is far simpler. Last place players get babysat with a huge advantage which pretty much makes going for pressure early game completely irrelevant. It is suicide to reroll early in TFT while it is a viable strategy in dota auto chess.
2. Shit balancing. Some units are totally useless while others are god tier. Not a surprise given how horrible league's balancing is.
3. Heavy burden of knowledge of the game. There is no way to look up item combinations or champion synergies in the game. You also can't look up the tier % for rolling so most people don't know when to stop leveling and start rerolling for their key units. Same thing with league where abilities now do 3 different things and most people don't know exactly what those things are. Key information is locked behind third party sites once again.
4. Game breaking bugs. League is already riddled with game breaking bugs so I guess it's also too much to ask for them to fix the bugs in this mode either.