Some reasons I don't use them anymore (in no specific order)

1. I have had them subtly mess with websites I am working on and I probably wasted multiple hours troubleshooting an issue that wasn't an issue

2. I have had them break a web form when I was trying to purchase something

3. I have purchased some things I like from ads and wouldn't have discovered otherwise

4. I don't frequent websites that overuse them or I can't work around them

5. I'm on a work laptop sometimes and I'm not allowed to use them for corp security reasons

6. I'm not sure I trust the ad blockers themselves, their developers, or their own app security

7. It's another process that can slow down viewing a webpage

Or AdGuard on a Raspberry Pi paired with Tailscale and never see ads on any machines you own again even on cellular.