for ref, I'm someone who has spent a HUGE amount of time/effort to avoid spammy services acting as a gateway to my brain for advertisers, self-host alt services that dont do this, & restrict notifs when I must keep a spammy service around
...and it still feels hopeless.
I feel so bad for non-technical people. I saw my grandma'a notification drawer when helping her w/ her phone, & it looked like a casino w/ 100s of attempts from various services to get her to buy or interact with their products