I've been playing with it and it's pretty straightforward. It's a self-custodial wallet that backs up an encrypted copy of your seeds to your Proton account. Given their good track-record with encryption and security, I see no reason to not trust the wallet. If something is revealed, and evidence is uncovered, that's a different story, but as it is, it seems to be a perfectly suitable wallet with excellent security geared towards the masses.
Discussion
I've used it. It's easy and beginner friendly not something you trust your life savings to.
I can co-sign to that. It's definitely not a pro wallet for real bitcoiners. It's an intro wallet than I think has been designed to be welcoming and easy for the normies.
Yes, would even make more sense if they implement https://spark.info/ L2 Bitcoin when released.