Muun isn't a "real" LN Wallet.

Muun works by using a lightning service provider that pays LN invoices for users through a smart contract. This is known as a submarine swap. When you make a lightning payment on Muun, the bitcoin is sent on chain to the lightning service provider along with the LN invoice generated by the user. That's why the fees are that high.

If you want it easy go with Wallet of Satoshi. Simple, but it's a hot wallet.

If you want it safe and you have big amounts of Satoshis I would recommend Phoenix Wallet.

It is Non Custody, what means you will get a 12 words seed phrase.

You will have to pay 3000 Sats to open a Channel and I recommend a big amount for the first transaction (for a bigger Channel).

That's why I use Wallet of Satoshi for my "daily" transactions and Phoenix as my "savings account".

Good Luck 😊