Solo Q does not reflect an individual players skill, unless it extremely overshadows the rest, for example high elo players.
For the rest of us, its a roulette of who got the smurfs, who had 1 or 2 players who throw it for the rest of us, or the low elo player who duos with a higher elo, but is so bad goes 0 10 in lane.. and makes the game a 4 vs 5, and plays an important role like adc or mid, and does a total of 5k dmg by the end of the game.
The next aspect is team comps.. quite often its just whoever picked the stronger champs wins, skills barely comes into it.
So with the amount of variables per game, the inconsistencies just make winning and losing just feel like a random hit and miss situation all too often.
The reflection of you skill and ability to play isnt there, the last time I felt that there was some of it was season 2/3, since then its just gone down.