nostr:npub1sqzr42dj8vx32yd5jcvvl3ytux45kl0etgf6y2ymjvmd7lqmuwmqk9vk7v app does a pretty good job with KYC free buying (under 1000euros/day). Only complicated part for grandma is having to sign a message if you want to transfer from the app's self-custody wallet to another one.