2. You can create multiple configs and easily switch between those
3. Works everywhere (Pi-hole is very cool but only works within the local network you set it up, AFAIK)
4. On my smartphone Blokada regularly stopped, probably because I use an energy saving profile. I could never keep it running for longer than a few days, no matter what I tried. NextDNS seems to work fine so far, had it running for some weeks without a single crash