I have used 1Blocker for several years and they currently have blocking on Safari and in apps and a firewall feature.
Is it necessary to use all the features in 1Blocker?
Are people using the firewall feature at all? I might suspect that the firewall feature sucks battery somehow or making the phone and iPad hot?
I don’t block comments, but otherwise use all the other filters and the firewall, and I’ve not noticed any major performance issues (iPhone 13 Pro/iPad Mini 6th Gen).
Great adblocking - I don’t see any ads on the sites I regularly visit.
A great win, if you don’t want to have your behavior manipulated.
I agree. And the fact that I can always quickly tab disable ad blocking to view a site works really well. Using the new firewall feature show that VPN. In the top right all the time though…
I turned off the firewall for one really good reason. You have to turn on the iOS VPN, but that puts “VPN” in a box by your battery level. I wasn’t used to it and my eyes kept going to it because it was strange. So I turned it off. 
I am mostly happy with 1Blocker. It used to block YouTube ads, but it ended up breaking YT in Safari last year for awhile (I don’t use the YT app on iPad). It no long blocks YT ads, even when updates say it will. I would change ad blockers for one that blocked YT ads.
Their VPN feature caused me issues with Tethering. Literally no devices were able to connect through my iPhone. Otherwise, I am using the standard Safari blocking, all filters on.
I had been a paying user of 1Blocker, but found that the feature bloat was getting more annoying than anything.
I also use NextDNS so the benefits were more limited.
Now I’ve switched over to Wipr which does enough and doesn’t have all the extra things to fiddle with.
My 1Blocker subscription is about to expire, so I’ve switched the sub so it doesn’t auto renew so see what happens, how much it slows down my browsing and how bearable it is.
I think 1Blocker is having an impact and making my web life better, but I want to prove it to myself.
This must be why my Personal Hotspot wasn’t working very well the other day. It wasn’t very urgent so after a while I just gave up and forgot about it. But I forgot I had the firewall/VPN turned on
Probably yes, it took me time to figure out it’s 1Blocker causing the issue. But once disabled all flow well.