AdGuard was my ad blocker of choice on Android for years, but man did they fall off a cliff recently. I used them when you could purchase a forever license (which I don’t even think is an option anymore?), and it was great. All ads would be blocked basically everywhere, whenever they’d sneak through it just meant there was a filter that was out of date and needed to be updated.
Then about a year ago, the shenanigans started. Non-stop emails like OP is complaining about but also - their service BROKE whenever my phone would switch from data to wifi or vice versa. Like, any time it switched network types, just no internet would work at all. I’d have to force quit AdGuard and suddenly everything was fine. The timing happened when android updated from 12 to 13, so I figured it was something to do with that and emailed customer service. I got a notice that said something like “due to high ticket volume, it may be SEVERAL WEEKS before we get to your ticket or acknowledge it is being worked on, thank you for your patience.” So they’re spamming your inbox non-stop trying to click farm, but they have nobody actually working on the product. I never heard anything ever again (still haven’t…account is still active, email is still the same). I tried reaching out 3 or 4 more times but I’ve never received a response.