Are there any strong competitors of Monero?

Not that I'm aware of, a couple have better technical privacy for now until the integration of full-chain membership proofs, but they are not nearly as used, and so you are trying to get privacy in a very small pool of people, which is not helpful.

Negative. Every single one of them has some massive red flags that make them nonviable.

It's the best Coin I've ever met. The one thing is that it's hard to buy on CEXes, so I need to use Exolix or simpleswap to do it

https://cashu.space/

Zano, Firo.

They might be small now, but in a few years they will grow. Better invest now while they're still cheap. It's like buying Monero at $10. They might be hard to buy now, but so is Monero.

Fast and low fees wins the privacy game. No one wants to wait for Monero sync to complete or 10 transactions to spend again, it's just bad UX.

Are there any strong competitors of Monero?

No. XMR are 100% mining rewards. Proven technology has been running since 2014.