That doesn't make it a non-shit ISP, though. And, honestly, there isn't a commercial VPN provider that I trust at all. Most of them are extremely questionable. I'm certain some aren't, and perhaps Mullvad is one of those, but it's impossible for me to know one way or another so I avoid them all.
For privacy I trust mullvad more than my ISP and I think they have the track record to back it up. If your ISP is shit in other ways then a VPN does not help of course.
All a VPN does is either move a bit of trust to the VPN or move your apparent IP to another ASN/location. The first of those can be helpful for dealing with some ISPs,
Honestly, though they are hyped a bit much to the general public, I have almost all my traffic on endpoints routed to ProtonVPN. Better than nothing and fuck ATT.
I dearly wish I had an option for a non-shit ISP. But my only option is Comcast.