Solo queue competitive mode is broken and unfun

Started playing when the game come out. Everything was very fun until I was able to play competitive. There are two major problems I see in the competitive mode.

The games are literally coinflip without much skill factor, because one of the teams always lack healers or tanks so they get annhilated instantly and lose.

The second major problem is: It's 90% of the time my team having the line up issues. The enemy team always have two tanks and healers but my team don't. Everyone wants to play DPS. I had to learn playing support to fill the support gap, but we still lack tanks or an additional healers in game.

I am not an esports pro wannabe or aiming to climb to the top of the ladder. I just wanna play and have fun but this is literally the worst ranked experience in any competitive game I ever played. And, I am yet to understand why it's 90% my team having the role problems, not the enemy.