The two capitals (Santa Cruz and Las Palmas) are pretty good spot to live in. Tourism focuses on the south on both islands. Las Palmas has a beach with a bit touristic activity, but its not drinking tourism like Mallorca or Benidorm. Combined with nice weather all year round overall a greaet place to live. Very walkable cities, you can do without a car. Due to nice weather, you can always go by bike or scooter. Taxis are cheap. Thanks to the tourists, cheap flights all year round, every day, to all major european cities.

But yeah, if you come with kids, factor in private schools. The public system here is broken. As for internet, I pay less than 10€/month for 500Mbit fibre - I couldn't even get that in Germany and if could it would be north of 80€.