GOS for my mother (70) a bad idea?

My mother asked me to buy a new phone for her. She's typical kind of mother running regulary into "IT problems". At the moment she's using a cheap Android phone which is full of bloatware. The ads confuse her a lot. I think about buying her a pixel 9a and install graphene OS. Since everthing should be also convenient and user friendly I would install play services and disable most notfications. Are there any reasons why this would be a bad idea?